Hi Vaping Community, In this review i take a look at the Siren V4 MTL RTA from Digiflavor. The Digiflavor Siren V4 MTL RTA was supplied for the purpose of this review by Allison from Geekvape.

S MTL RTA V4 - Digiflavor


Geekvape’s sister brand Digiflavor have a few favourite series in their camp but maybe the one which is held in the highest regard especially amongst MTL vapers is the Siren with the Siren V2 22mm version still regarded as one of the very best MTL RTA’s ever to be released. There was a long wait for V3 and if that was a little disappointing to some it’s been swiftly followed by the V4 which see’s a radical makeover and semi-hidden bottom airflow design. The V4 comes with 2 different drip tips including the Siren style and 4 different coils, let’s check out the Siren V4 from Digiflavor!

In The Box


1* Siren MTL RTA V4
4* Feather Cotton
1* 510 Drip Tip
4* DIY MTL Coil
1* Spare Parts Pack
1* Tri Tool
1* Manual


The Siren V4 came in sample packaging that consisted of a Red cardboard box with outer White cardboard sleeve, we have the “Digiflavor” logo front and contents etc on the reverse! I received the Gunmetal version, the options are Gunmetal, Rainbow, SS or Black.

The Siren V4 is a very short 22mm MTL RTA with just a narrow PEI viewing tube which is frosted on the Gunmetal and Rainbow versions but Ultem style on the Silver and Black versions! The top cap steps in and has fine aggressive knurling, we then have a very long narrow drip tip. On the main sleeve we have the “Digiflavor” logo printed on the front which looks ok in my opinion but may not be to everyone’s liking. On the base section below the frosted tube and on the airflow control ring we have the same fine aggressive knurling to match the top-cap. Between the two we have an indented section which includes airflow markings and a Red dot on the AFC which can be lined up against those markings!

Moving to the base we have a Gold plated Brass pin that protrudes and printed branding and safety markings. It’s a noticeably small and short RTA and in my opinion quite a looker!

Siren V4 MTL RTA Specs and Features:

Dimensions: 22 x 28.5mm
Capacity: 2ml
Stainless Steel
PEI Narrow Tube
Thread: 510
Filling: Top fill
Included Coil: Braided Coil(0.65Ω); MTL Fused Clapton(1.0Ω); MTL Fused Clapton(1.2Ω); MTL Clapton(1.4Ω)
GTA design deck, easy to build and trim
Semi-hidden AFC structure, precise airflow
4 Different kinds of MTL coils
Colour: Gunmetal, Rainbow, SS, Black

What You Receive?

As well as the Siren V4 MTL RTA with pre-installed long narrow 510 drip tip you also receive what i would describe as a Siren style shorter (but still quite long) alternative. I would imagine it’s more to do with mine being a sample but the alternative drip tip didn’t have the O-rings fitted so was loose but were in the bag of O-rings and spare grub screws so needed installing.

So that’s the spares bag mentioned so on to the two packets of cotton and coils! One packet has 2 different 2.0ID coils which are a MTL fused clapton (1.2ohm) and a MTL Clapton (1.4ohm), you also receive 2 shoelace cotton pieces. The second packet consists of two 2.5ID coils which are a Braided Coil (0.65ohm) and a MTL fused clapton (1.0ohm), again you receive a further 2 shoelace cotton pieces, finally you receive paperwork!

It’s Various Parts!

Up top we have fine aggressive knurling on the top cap which sounds a little squeaky when unscrewing and securing but actually feels very smooth! We have a narrow, very long drip tip pre-installed which can be swapped for the Siren style drip tip which in my opinion despite the V4 having a complete aesthetic overhaul and being much shorter still becomes visually a Siren in appearance with this drip tip installed, I like both!

The next section is all one piece which includes fill plate with two fill ports, outer sleeve, chamber and narrow PEI tube, you don’t get a spare PEI tube but maybe that’s because it can’t be removed, at least i can’t find a way of separating it from the sleeve which if is the case must be a con because if it cracks the whole top section needs replacing!

The deck section has a 2 post GTA style deck with shower head airflow holes underneath where the coil will sit. We have an AFC which can be removed which has a Red dot for lining up with the airflow markings!



The Siren V4 has a 2ml capacity and top-fill design. As mentioned even if it doesn’t sound it the threading is nice and smooth and removing the top-cap reveals the fill plate to be indented allowing any spill to find it’s way into one of the fill ports which are not huge but big enough for most nozzles.

The Airflow!

The main talking point is the airflow which consists of a semi-hidden design! When removing the airflow ring you can see notches which means everything will be lined up correctly when installed and an indented rail that adjusts against five 0.6mm airflow holes on the base section.

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When the ring is installed the airflow holes are completely hidden and you adjust the Red dot on the AFC against markings on the base, essentially the higher on the scale the Red dot is positioned the more of the airflow holes (or partial holes) are exposed to the indented rail which opens the airflow! You can have just one 0.6mm partially open right up to all five 0.6mm airflow holes fully open!

The Deck and Build!

The Siren V4 has a GTA style deck with 2 post design, side terminal openings and Gold plated flathead screws! The wicking channels despite being a GTA style deck have floors rather than being open bottomed, those floors have 3 wicking holes in each!

Your coil leads slide into the terminals from the side where we can see the openings are curved upwards acting the same as lips in regard stopping your leads popping out while fixing in position. Use a coiling rod to place the coil in position and fix each lead one at a time holding the lead in position while tightening down from above especially if using thin wire as there is a gap between the bottom of the screw which acts as your clamp and the inside edge of the terminal! Once your leads are fastened in place use the coiling rod or fit for purpose tool to manoeuvre into the ideal position, then snip your access leads (there is plenty of room), give your coil a few low wattage pulses and strum out any hotspots!

Wicking is a doddle (in fact it’s a very easy build) and is helped with those floors to the wicking channels telling you that your ends need cutting short, simply fluff up and place into the channels! Then you can prime your build and give it a few pulses to admire your work before screwing the tank together and filling!

How It Vapes And Thoughts!

I love this MTL RTA which is strange because the amount of cons i found leaves me scratching my head to why i like it so much, maybe i am just shallow and find to me what is it’s stunning looks is ruling my head but there is far more to it than that which i will come to.

So what about those cons, well nearly all are to do with viewing the e-liquid whether that’s while in use or while filling! The very narrow frosted PEI tube only allows the level to be seen when the tank is almost empty and even then only in good light, yes in decent light you can tilt and get some idea but i want to be able to just glance at a tank to see the level which isn’t possible with the Siren V4! Again having mostly a metal sleeve with just the lower narrow tube means when filling you have to use the fill port you are not using to fill to judge the level which again needs good light and is far from ideal and will probably cause many to slightly underfill turning a low capacity 2ml RTA realistically into about 1.5ml to 1.75ml! Then we have the PEI tube which doesn’t seem to detach from the main sleeve which is a big con for me and if it’s just tight and actually does undo still a con that i would be worrying about using force to remove it. My other con is although the tolerance on the AFC is spot on it won’t turn while on the device so if I want to adjust airflow during use i need to first remove it from the device which is annoying!

So why do I like it so much other than it’s good looks? Well firstly it’s that semi-hidden airflow design which is so well thought out and allows the precision of the airflow setting to be as precise as with atomizers that come with inserts that need fitting. Next is smoothness which is something that is very important to me, the acoustics of the tank allows for the crackle of the coil to be easily heard but to a background of silence as this gives such a silky smooth and silent draw. Next is it’s credentials as a true MTL RTA with airflow going from extremely tight up to a loose MTL but not over loose so you would need this fully open and to use a wider bore drip tip to have any chance of a RDL draw! The build and wicking is straightforward and I have had zero leaking which surprised me along with just how tight this will go bearing in mind we have a showerhead airflow outlet under the coil which usually does restrict just how tight the draw can go and also can be prone to leaking, so both surprised and very happy!

I also like both drip tips and that you get 4 different coils plus 4 shoelace cotton pieces and then we come to flavour which is as good as with my other very best MTL RTA’s like the Bishop and Glaz Mini, this has particularly been excelling with Bakeries, Desserts and Fruits!

So to sum up, despite being aesthetically so different, much shorter and with a different airflow design we have a Siren which is a worthy successor to the Siren V2 22mm MTL RTA, it’s been a long wait!



Stunning and cute looking (in my opinion)
22mm and short (usually is a recipe for flavour in my experience)
4 Colour options
Semi-hidden airflow design
Precise airflow adjustment
True MTL RTA, extremely tight to loose MTL
Smooth top cap threading
Easy build and wicking
Super smooth draw
Quiet apart from crackle of coil
Excellent flavour
Zero leaking or flooding
Wicked like a dream
Includes 2 narrow drip tips (like both)
Includes 4 different coils and shoelace cotton


Can’t detach PEI tube from main sleeve
Difficult to see juice level during use
Difficult to see juice level when filling
The above can mean under filling what is a low capacity tank anyway (2ml)
Can’t adjust airflow ring with the tank on a device

I would once again like to thank Allison from Geekvape for supplying the Digiflavor Siren V4 MTL RTA for the purpose of this review, thanks for reading and stay safe!

S MTL RTA V4 - Digiflavor


Really like the way you told the story in this one, Tim! Well done :+1:


Cheers mate, much appreciated!


Firstly @Timwis yet ANOTHER, honest, through review. I LIKE the fact that you dropped the cons, as you saw them, AND, you stated your honest opinion, none the less.

I don’t want to mention the MTL (very old tech) that I’m still using, but soon my stash will run dry, and I really need to get some more MTL setups, and you are making it very hard, AND, easy, at the same time.


VERY well said @whthek.


And the Bishop which in my opinion is number 1 i haven’t even reviewed!


Nice review @Timwis, and somewhat thought provoking.

As I am solely a MTL vapist and prefer a tightish draw, both the OG and V2 Sirens very much disappointed due to the “showerhead” airflow which prevented this. I find it interesting that this time it appears they have made the airflow tighter without changing the outlet design. If so, this is a huge plus in my opinion.

The PEI tube is a bit annoying, though when I had a 22ml Berserker with a metal sleeve, using TC mode let me know when the juice was too low. However, it not appearing to be replaceable is an issue. 2ml capacity is always a turnoff for me, though the smaller size could counter that as most of my RTA’s are 24mm and/or have bubble glass.

I will wait to see if and when it is stocked by my suppliers and actually consider this one based on your review. Always open to trying new MTL RTA’s if they will truly restrict the airflow enough for my preference.

Really mate? They have come a long way over the last few years, say’s he who still uses OG Berserker RTA’s in his daily rotation… lol


Yes mate as with the Tauren MTL RTA it seems using a semi- hidden track to adjust allows for a tight draw despite that shower head! After the Aries1, earlier Sirens and MD i was expecting a loose draw and maybe a bit of leaking but no, this goes really tight, zero leaking and super smooth draw!


Don’t know it it’s just me but i found the 22mm Siren 2 far superior to the 24mm!


Ares 1 for me was just WTF! Especially given who the collaborator was. So loose it wasn’t funny. The MD seems to be very much build dependent. I am running one at the moment which is working ok with a 3mm ID coil and the smallest air hole.

I only tried the 24mm so perhaps the issue was there…


Yeah the two are chalk and cheese, amazing how just diameter can make so much difference with a design!


just to add i recently received this atty for some MTL action and the PEI does come out, its press fit and has an O ring round the top and slides off the inner metal casing ( need a bit of a wiggle… mine came out when i unscrewed it and fit back in just fine… there is a 4ml version out there ( non tpd ) so its just a case of hopefully being able to source the 4ml PEI to make this an absolute winner… mine will be going on my EHPRO 101 or my Voopoo Drag X plus ( undecided yet and will see when both mods arrive tomorrow which one it looks best on ).


Thanks mate for that info and welcome to VC! :beers:


Welcome to VC @elvedhel ! :wave:


I have the original bezerker that I traded a profile m mesh rta for. Idk for me the AF is so tight no matter what coil of flavor I use i don’t get much if any flavor…just nic effect really lol.I make good juice and know how to install a coil n wick properly but I actually hate the atomizer haha.I have the innokin Ares 2 and the newest bezerker 24 mm and 22 mm Rita and I don’t get a tremendous amount of flav out of any of them but love the long lasting battery n how little of juice they use with a .8ohm coil at 18w for example.Idk maybe these really low watt tight draw attys need extra flavoring but I’ve use shelf brands too( salt nic 25 mg mainly) I recently got an Ursa Arbitor solo restricted Dtl Rta n used a lower ohm coil .4ohm at 35-40 Watts and made all the diff in the world.I mean still not nearly as flavorful as my mesh and reg coil Dtl rtas at 55 Watts.I guess what Im tryna say is I want to love mtl and use less of my nic,flav, concentrates,better battery time but I don’t.I know people are different but I seem to get more flavor out of my little novo 3 pod than any mtl Rta but I don’t know why that is.Ever since I won a free wotofo profile m mesh Rta I’ve never looked back and have been buying mesh and Dtl rtas of all types ever since so I deal with more charging of the higher watt settings and buy lower ohm coils n mesh strips etc.I suppose more airy bigger clouds( which I could care less about) must be my nitch.I even get good flavor from the Rba section on my 40w boost pod mod single wire high ohm coils i wrap(prob cause I can open AF dial up) but these tight draw tanks nothing to dance over.Idk maybe its just me or expect more than I ever get.I never had a kayfun lite or high end one but not sure it would make that much diff after buying 3 diff mtl Rta.Ive tried the vandy vape superfine mtl clapton wire at .6ohm but even that had moderate flavor.Sorry so long I just don’t know what could be causing way better flavor at higher Watts other than more heat and airflow equals way better flav but I know people all the time who argue the opposite who vape at a mere 11 Watts and swear by mtl.Conclusion- 50w 10 mg salt nic in a good mesh Rta .2ohm or .18ohm mesh strip with AF half closed is the best vape that makes my DIY recipies really soar and no longer look at mtl rtas.What am I missing here? Any ideas would be appreciated but I just may not be a mtl guy and have only really tasted mint menthols n other strong flavor but fruits and desserts and 40 other recipies I make-nothing spectacular n gonna stick with what what works for me :pray::boom::sunglasses: