62 million smokers and vaping enthusiasts reached since 2015!

Wotofo & SuckMyMod COG RTA: Geared Toward Innovation

Spyros Papamichail
May 29, 2020

Product intro and specs

The COG MTL RTA comes from Wotofo’s latest collaboration with Matt Culley from Suck My Mod (SMM). It is a 22 mm mouth to lung RTA with a PCTG tank section that fits up to 3 mL of juice. So far so good—but there’s more to it. Peeking at the bottom of the base, you can see the feature that sets this RTA apart from other MTL tanks. The COG houses an innovative, gear-like airflow mechanism that allows adjusting the air intake right under the coil without making use of inserts.

“Wotofo” and “MTL” are not two words that we are used to seeing next to each other. In fact, as far as I know this is just the second MTL atty to ever come from Wotofo, with the other one being the STNG RDA. I wasn’t a big fan of the STNG as I found its airflow to be a bit too “sloppy” for a good MTL draw. Let’s see if the COG with its innovative airflow adjustment design can prove that Wotofo can do MTL right this time.

This RTA was sent to me by Wotofo for the purpose of this review.

Price: $34.99 (At Element Vape)
Colors: Black, stainless, gunmetal, blue, gold, rainbow.


  • Type: MTL RTA
  • Drip tip: 510 Delrin
  • Tank capacity: 3 mL
  • Tank material: PCTG
  • Body material: Stainless steel
  • Diameter: 22 mm
  • Height: 34 mm (without drip tip & 510 pin)
  • Airflow type: Bottom airflow
  • Coil configuration: Single coil
  • Recommended coil resistance: 0.4-1.8 ohm
  • Resistance of included coils: 0.8 ohm / 1.2 ohm
  • Insulator material: German PEEK
  • Connector Threading: 510 thread

Kit contents

  • 1 x COG MTL RTA
  • 2 x 2.5 mm cotton strips
  • 1 x Dual-core fused Clapton coil 0.8 ohm
  • 1 x Single-strand coil 1.2 ohm
  • 1 x Cross head screwdriver
  • 1 x User manual
  • 1 x O-rings bag

Build quality and design

Let’s start with the basic specs. The COG is 22 mm in diameter, which means that it will fit to the vast majority of vape mods out there. Most mods nowadays will fit atomizers with a diameter of at least 24 mm, but I am sure that some people would want to pair the COG with size-restricted mods like the original Pico. It also has a 3 mL capacity, which is more than enough for an MTL RTA—most 22 mm RTAs usually go up to 2 or 2.5 mL.

I received the gold edition, which is the one I like the least out of the lineup. But outside of that, the tank looks gorgeous with its semi-transparent top cap which creates an interesting effect, making the bell seem like some type of an exhibit. And the underside of the base with the visible red cogs is a very interesting design choice. All in all, I really like the looks of this RTA—it has a certain type of high-end feel to it. I was also happy that the plastic tank is not threaded on metal anywhere, because this was one of my major concerns coming into it. The only downside: the awkward “CE” and bin carvings on the bell. I am guessing that the transparent design prevented them from placing these at the bottom of the tank, but they don’t look good in my opinion.

Note: Make sure you don’t wash the PCTG tank with very warm water, as this may melt it. Also note that some juices (mostly juices with citric flavors) are known to crack plastic tanks—although PCTG is supposed to be more resistant than other types of plastic.

From a build quality perspective, the COG has some issues. The PCTG tank may resist some falls, but my top cap already has a crack on it! It’s not juice related (the crack is on the exterior of the cap) and I may have dropped it at some point, but I sure didn’t drop the whole tank. As far as I am concerned it might have been there out of the box. I am also not a big fan of the way the bell is screwed on the tank. I used a thin screwdriver and it chipped on me, and I had to search through my toolbox to find one that would fit well. Talking about disassembly, Matt noted in his presentation that users should not try to remove the base, as this will render the RTA unusable.

Finally, I would have liked them to include an extra tank and maybe an extra drip tip. As far as kit contents are concerned, the COG ships with the bare minimum; two strips of 2.5 mm cotton, two coils, O-rings, a screwdriver and replacement screws.

Building and wicking

The COG RTA features a Kayfun-style deck with two clamps to secure the coils. It is a forgiving deck and super easy to build on. The coils can be mounted from both sides, so the orientation of the wraps is not important. Just make sure that your wire ends are positioned at the bottom side of your coils before mounting, as this will allow for easier adjustments.

To build the COG you just need to place your coil ends under the clamps and secure them by screwing the Philips head screws. When your coil is in place, make sure you use your jig to move it a bit closer to the airflow hole. Then cut your wires flush to the deck—there’s not much clearance there, so you may want to put the tank together and check for shorts at this point. Remove any hotspots if you are using a non-spaced coil, and wick it up. I suggest cutting the cotton tails around 1-2 mm from the outside of the wick channels, which will allow your wick ends to float a bit higher than the base of the deck.

The deck can accommodate up to 3 mm ID coils, and that includes exotic MTL coils like thin fused Claptons. You could even go 3.5 mm with thinner round wire, but I don’t see any reason for it. I got the best results with 2.5 mm coils, and this ID allowed me to get away without combing my wick ends. But for anything larger than that, I suggest slightly combing before placing the cotton inside the wick channels. Just don’t overdo it and you should be on the clear when it comes to leaking.


What sets the COG apart from other MTL tanks on the market, is its innovative airflow mechanism. The premise is simple: many MTL RTAs have failed to give a “proper” MTL draw because they are making adjustments at the base of the RTA, which may choke the airflow and/or cause turbulence. Other MTL RTAs employ airflow inserts, which do work most of the times, but do not allow on-the-spot adjustments. The COG RTA aims to solve both these issues by using the airflow ring to adjust the airflow right below the coil through a gear mechanism that seems like it was taken out of a car transmission.

What happens is this: every time you turn the airflow ring at the base of the RTA, a mechanism that’s right under the deck turns with it. Each step is connected to a small ring that clicks right under the airflow hole. The air enters through the two large slots, gets channeled through the hole of the ring, and hits the coil from directly under it. In a way, it’s like having five different inserts. The IDs of the holes are 0.8, 1, 1.2, 1.4 and 1.6 mm, but as you will see in the next section, the numbers may be a bit misleading.

Wotofo COG performance

I tested with COG RTA with the included MTL Claptons, some MTL staple coils, and my go-to MTL build; six wraps of slightly spaced 26-gauge Kanthal. I briefly described the airflow system, but with the cogs being the real star of the show here, let’s see how they affect performance.

The airflow on the COG is smooth all across the board. But while the five airflow levels are distinct to one another, they are not that much different to each other. For starters, the 0.8 mm setting feels more like a 1.2 mm hole. I put it next to the Innokin Zlide with two holes open and the COG is maybe a tiny bit tighter. Then, I managed to get a similar airflow to the three holes of the Zlide when using the COG at its largest airflow setting. I would have liked the airflow settings to be more diverse, but I found my draw at the middle setting, so that’s a non-issue for me. If you want a super tight, Berserker-style MTL, or if you want a versatile airflow, then the COG may not the best option for you.

The flavor I get from this RTA is hands down some of the best flavor I’ve gotten from an MTL atty at this price point. I get a warm, condensed, and flavorful vape out of the COG and I am sure that flavor chasing MTL vapers are going to be more than satisfied by it.

But there’s one more thing I’d like to discuss from a performance standpoint. I noticed that once in a while I’d get a drop of juice in my mouth. Checking under the drip tip, I saw that juice would find its way there and, eventually, through the mouthpiece. This is common for MTL atties, but it feels like it happens more often on the COG. I swapped the O-rings (even though it’s only three of them and not positioned anywhere that would make a difference), repositioned my builds, re-wicked a couple of times… The two things that fixed it to a great extent were screwing the bell tighter on the tank and using a drip tip with a slightly wider bore. It still feels that there’s more juice accumulating there than it should, but it is manageable and not a deal-breaker.

Pros / Cons

  • Good build quality
  • Great looks
  • Will fit in practically every mod (22 mm)
  • Great capacity for a 22 mm MTL tank (3 mL)
  • Easy to build and wick
  • No leaking if wicked right
  • Airflow mechanism works great
  • Smooth and fine-tunable airflow
  • Very satisfying MTL draw
  • Great flavor
  • Plastic cap doesn’t thread on metal
  • No replacement tank or extra drip tip included
  • Hard to remove the bell from the tank section
  • Condensation under drip tip (requires troubleshooting)
  • Small crack on my top cap
  • Airflow options feel very similar to each other


Do I recommend this RTA? I don’t think I can respond to that with a straightforward yes or no—it depends on what you want out of the airflow of an MTL tank. It doesn’t get super tight, and the airflow settings are too similar to one another. If you are after an RTA that goes from a kinda tight to a slightly airy MTL, the COG will satisfy you just fine. The flavor is great, the airflow is smooth, and it looks absolutely great.

All in all, the COG is a great RTA for MTL vaping. It requires some trial and error when it comes to the seepage that makes its way under the drip tip, but it makes up for it with its overall ease of use. I will keep using this one, and I have to give it to Wotofo; it took them a while, but they did produce a solid MTL tank out of their collaboration with SMM.

Having quit smoking using vapes in 2016, I quickly developed somewhat of an obsession with all things vaping. I managed to turn my hobby into a full-time job, and I now work as the content manager here at Vaping360. In my free time you'll find me gaming on my PS5 while playing fetch with my dog, Buffy.
Notify of
Inline Feedbacks
View all comments