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Trends Uwell Caliburn GK2 Kit Review – Light Up Your Life

The Caliburn Family” from Uwell is still growing. Let's welcome the 8th member - Caliburn GK2, which is an upgraded version of KOKO Prime.

You know, Uwell Caliburn G2 was released with a pod that could be flipped to allow for two different styles of vaping. And Caliburn A2 was their first release to feature a juice viewing window while the G2 utilised progressive airflow adjustment and vibrating feedback.

1 Caliburn GK2 Review Caliburn Timeline

After these releases, Uwell merged the Caliburn G2 Pod with the form factor of the KOKO series to bring us Caliburn GK2.

What’s new for the Caliburn GK2? Let’s take a look.

2 Uwell Caliburn GK2 Review

What Can We Expect From Uwell Caliburn GK2 Kit?

Unlike Caliburn G2, there’s no finger firing – just auto-draw. That’s something I’ve become very used to of late but I’ve always been a lazy bugger!

3 Caliburn GK2 Review Box

It’s a cost-effective proposition too because it’s not a sealed pod system. Refill with your own liquid at any time. The replaceable coils are cross-compatible with three in the Caliburn G series so that’s also good to know.

Those coils use the Uwell proprietary pro-FOCS flavour testing technology – a reason why the vape quality is usually so impressive.

The progressive airflow adjustment of Caliburn G2 has also made it across so flavour intensity and vapour production can be altered to suit.

..OK! We get the same pod as G2.

Expect to pick the device up in four different colour schemes. Ribbon red, Matte Black, Aurora Green and the one I’ve been sent, Ocean Flame.

4 Caliburn GK2 Review Colors

Design & Build Quality

5 Caliburn GK2 Review Components


It’s starting to become a trend for devices to have additional flashing lights and Caliburn GK2 capitalises on this. The front panel features various coloured lights that illuminate to reflect current battery life or potential safety issues.

Vibration feedback is also included and is most noticeable when slipping the pod into the battery section.

With these two designs, vapers will have a better interactive experience.

6 Caliburn GK2 Review Dazzling Design

Well, the important thing to note is how incredibly light it is. Despite being a box design the slim nature means it’s very comfortable in the hand. It’s also quite easy to conceal for those moments where stealth is utmost.

The main panels have a silicate glass coating which gives them a very polished feel. Only time can tell whether it’s resistant to knocks and scratches. The colour gradient around the edges of the kit is quite effective and gives it plenty of character.

7 Caliburn GK2 Review KOKO Side

This side features the colour razzmatazz!

The lanyard clip is contoured around the top corner and never gets in the way when vaping.

8 Caliburn GK2 Review Lanyard Fixing Clip


As previously mentioned this is basically the same top filling pod as included with Caliburn G2 complete with a progressive airflow adjustment wheel.

9 Caliburn GK2 Review Airflow Adjustment Wheel

The pod is transparent with maybe a touch of frosting, so viewing the remaining juice levels is easy whether inside or outside the battery section. And its top-filling design makes it convenient and clean, no need to worry about getting your hands dirty.

10 Caliburn GK2 Review Juice Viewing Window

There is a stiffness to the mouthpiece when removed for the purposes of filling. It’s fixed into place via two clips on the pod which I found quite difficult to snap off. Those with dexterity issues may find themselves becoming frustrated.

I’m also concerned that over time the PCTG plastic will crack or split.

Caliburn GK2 is compatible with 3 Caliburn G series coils: Caliburn G2 1.2Ω meshed coil, Caliburn G 0.8Ω meshed coil and Caliburn G 1.0Ω coil. The kit includes 1.2Ω and 0.8Ω two meshed coils. More flavour options are provided for vapers.

11 Caliburn GK2 Review Coils

Battery Section

Like Caliburn KOKO Prime, Caliburn GK2 is powered by 690mAh built-in battery with max 18W power output.

The underside of the battery section is home to the type C USB charging port which is sensibly recessed. This does mean horizontal charging so I recommend removing the pod and leaving it in a vertical position to prevent any cotton from drying out.

12 Caliburn GK2 Review Type C Charging Port

There are also three venting holes for the 690mAh battery. That’s a nice touch! We can never be too careful.

Flashing Lights – What Do They Mean?

As hip and cool as these coloured lights may appear they do serve an important purpose.

13 Caliburn GK2 Review Vibrate

During the vape, a glimmering green light indicates battery strength is more than 60%. When it turns blue it means the battery has between 30% – 60% charge. Anything less is denoted by a red glimmer.

There’s an 8-second vape cut-off incorporated so when the lights glimmer green 5 times and send out 2 waves of vibration you’re overdoing it!

When the red light flickers constantly and the battery vibrates three times it's time to recharge the kit.

The lights also serve to warn of any potential safety issues:

Short circuit protection. Yellow flicker x 4, vibration x 4

Low voltage protection. Red flicker x 10, vibration x 3

Overtime protection. Green glimmer x 5, vibration x 2

Open circuit indication. Blue flicker x 3, vibration x 2

The lights will also flicker when the pod is attached or removed from the battery section. The colour depends on the current state of the charge.

How Does Uwell Caliburn GK2 Kit Perform?

1.2ohm Caliburn G2 mesh coil

I started by using the installed 1.2ohm G2 mesh coil with a Mango, Passionfruit and Blueberry e-liquid with 3mg freebase Nicotine and a 50VG/50PG juice ratio.

14 Caliburn GK2 Review 1.2ohm G2 Mesh Coil

To be honest it was quite a bland affair across the airflow restrictions available. There clearly was flavour but it was only the Mango that pulled through. It was quite flat, lifeless and lacking any clarity of sorts.

There was also a distinct lack of any sweetness. I expected more from the trio of fruits this profile was promoting.

Towards the end of every exhale I noticed more of a tasteless vape and more in the way of warm vapour alone. As mentioned, various airflow settings were tested and even a tight restrictive MTL didn’t improve the flavour output.

However, vapour production was on point producing thick dense clouds with the progressive airflow adjuster wide open. There were no issues there at all.

I went on to try some of the Bar Juice 5000 refillable e-liquid range which is known for its flavour intensity. Although things did improve it still fell short of what I expected in terms of sweetness, clarity and sparkle.

0.8ohm Caliburn G mesh coil

I used a couple of different flavours when testing the 0.8ohm G mesh coil.

15 Caliburn GK2 Review 0.8ohm G Mesh Coil

One was a simplistic, generic Peach e-liquid and the other was a slightly more complex flavour in the form of Arctic Roll – a dessert-inspired juice.

The Peach one had a juice ratio of 50VG/50PG and I have to say it absolutely trounced the 1.2ohm G2 coil for flavour. The fruit was both sweet and juicy and came through lively and intense.

Even the Coolada was highly effective, leaving a searing, icy effect on the back of the tongue. In fact, I really couldn’t have asked more from the coil.

It was the same with the 70VG/30PG Arctic Roll e-liquid. The spongy texture and cream-like qualities were all evident along with the subtle hint of Strawberry that I’ve come to know and love from this profile.

Vaping this juice ratio isn’t an issue for the 0.8ohm resistance coil. I got zero signs of any dry hitting and both flavours remained consistent throughout the duration of the exhale.


+   Excellent flavour from 0.8ohm mesh G coil

+   Good vapour production from both coils

+   Lightweight and pocket friendly

+   Super fast type C USB charging

+   Scratch-resistant silicate glass panels

+   No leaking

+   0.8ohm coil copes with e-liquid from 50/50 to 70/30 VG/PG


-    A relative juice guzzler for such a low-powered device

-    Pod fits very loose inside the battery section

-    1.2ohm mesh G2 coil underperforms

-    Some may have difficulty removing the mouthpiece to fill (subjective)

Final Review Verdict

 17 Uwell Caliburn GK2 Review

Battery Performance

I need to start by mentioning how quick the type C charging really is. I was pretty gobsmacked to discover it took only 30 minutes to rejuvenate a spent battery.

During the charge, the light shown on the panel passes through red, blue then green. Once fully charged it vibrates once and the green light remains on.

I managed a good seven hours from a single charge and this was under normal vaping patterns. Chain vaping will and does significantly reduce uptime. During usage time I topped the pod up twice.

Coil Performance

I have to say I was disappointed by the performance of the 1.2ohm G2 mesh coil. There’s always the possibility the cotton had lost wicking properties since it was pre-installed in the pod – it’s hard to know.

Either way, the flavour was dull, flat and uninspiring with the liquids I threw at it. It didn’t take long before I was reaching for an alternative vape.

By stark contrast 0.8ohm mesh G coil behaved impeccably, more than making up for the inadequacies of G2.

In both cases, vapour production was on point and delivered as expected for a lower-powered device. Plenty of clouds, swift dispersion.

Neither coil leaked from the base either which was good.

You’ll be better off using a 50VG/50PG juice ratio when using the 1.2ohm G2 coil but I had no issues using a 70VG/30PG e-liquid when testing the 0.8ohm G coil.

Progressive Airflow Control

Is it a gimmick? Not really although you shouldn’t expect too much from it. When fully open, I was able to take a restrictive direct lung hit.

There was only a marginal difference when closing the wheel halfway. At three quarters closed things became a little blurred because I was expecting an MTL vape to kick in. It didn’t.

The airflow restriction was simply too tight to work. You can MTL but it’s a very uncomfortable experience. The wheel needs to be around 1/3rd open before a decent vape can be achieved.

In some ways, it proves the fiddly nature of such a small wheel. You’ll also need good eyesight when fine-tuning it – which these days, I haven’t! lol

A touch of airflow turbulence occurs when the restrictions are too tight and it can feel like you’re trying to blow up a party balloon!

I got the best airflow performance when the wheel maximised airflow. It was a quiet, turbulent free vape with restrictive properties that are right up my street.

Design Issue

This one was a major frustration. The pod is far too loose-fitting inside the battery section. That could be because the lug cutouts inside the battery appear too wide or too big. The corresponding notches on the pod aren’t that prominent either.

Put simply, they don’t make a very firm connection.

On quite a few occasions the pod sprang up which caused auto to draw to fail, hence the frustration. Another time the pod just fell out completely, landing on the floor with the coil separating from the pod.

It’s definitely an area that Uwell needs to address in my humblest of opinions – of course.

..Oh, before I go. As promised earlier. The side-viewing window works just fine. It’s so much more convenient than having to pull the pod out every time to check.

16 Caliburn GK2 Review Hand Check

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