At a Glance
The Eleaf iStick X40 Mod Kit with GTL X Tank is a compact, MTL-focused box mod: 5–40W from a large built-in 3000mAh battery that Eleaf rates up to three days of heavy use, a 1.05″ TFT colour screen with five UI themes, and a removable-cell, recyclable design. It pairs with the classic GTL X tank — top airflow, slide-to-fill — and runs the full GTL coil family, including the upgraded dual-mesh GTL-D coils. Full details on the Eleaf iStick X40 product page.
Key Specifications
| Spec | Detail |
|---|---|
| Size | 36.7 x 24.4 x 129.5 mm (with 3ml tank) |
| Battery | Built-in 3000mAh, removable/recyclable design |
| Output | 5W–40W |
| Charging | USB-C 5V/2A fast charging |
| Screen | 1.05″ TFT colour, 5 UI themes |
| Tank | GTL X, 3ml / 2ml, slide-open top fill, top airflow |
| Coils | All GTL coils; bundled GTL-D mesh |
| Bundled coils | GTL-D 0.8Ω (13–18W) · GTL-D 1.2Ω (10–13W) |
| Controls | Power on/off, adjust wattage, button lock/unlock |
| Firmware | Upgradeable |
Battery: Power, but Make It Last
The 3000mAh cell is the reason to pick this kit over a slimmer pod. Eleaf rates it for up to three days of heavy use on a single charge, and 2A USB-C fast charging keeps downtime short. Unusually for a built-in battery, the design supports simple cell removal for recycling, so it is built with longevity and disposal in mind. For a low-wattage MTL tank like the GTL X, that battery capacity realistically means a full day or more for most users.
The GTL X Tank and Airflow
The GTL X keeps MTL clean and simple: a slide-open top-fill design you operate one-handed, and an adjustable top airflow ring that gives a satisfying draw while reducing leakage. Because the air enters from the top rather than the base, you get less e-liquid weeping during normal carry. The 3ml capacity (a 2ml variant is also offered) is sized for efficient mouth-to-lung vaping rather than big reservoirs.
GTL Coils and Flavour
The iStick X40 is compatible with all GTL coils, but the highlight is the upgraded GTL-D dual-mesh coil. It uses heat-resistant natural cotton with an optimised mesh thickness and fibre structure that absorbs and delivers e-liquid more efficiently — giving a longer lifespan and more consistent flavour. The two bundled resistances map to two feels: the 1.2Ω at 10–13W is a cooler, tighter MTL draw, while the 0.8Ω at 13–18W opens up a touch for warmer flavour.
Screen, Themes and Controls
A 1.05″ TFT keeps wattage, coil and battery status legible, with five UI themes to personalise it. Controls are deliberately simple — power on/off, hold-and-adjust wattage, and a button lock/unlock for pocket use — backed by a quick operation guide so it is usable right away. Firmware upgrade support means the device can gain improvements rather than being stuck at launch performance.
Pros and Cons
- Pros: Huge 3000mAh battery (multi-day); 5–40W with a clean MTL tank; removable/recyclable design; slide top-fill + leak-resistant top airflow; broad GTL coil compatibility; upgradeable firmware; clear TFT with themes.
- Cons: 40W and the GTL X keep it firmly MTL/RDL, not sub-ohm clouds; the 3ml tank is modest; it is larger than a slim pod kit.
Verdict: Who Is It For?
If you want MTL flavour with genuine battery endurance and simple controls, the iStick X40 is an easy recommendation. New to choosing between pods, pens and box mods? Read our beginner’s guide to your first device.
Frequently Asked Questions
How long does the iStick X40 battery last? The built-in 3000mAh cell is rated up to three days of heavy use and recharges over 2A USB-C.
What coils does it use? All GTL coils, including the upgraded dual-mesh GTL-D; the 0.8Ω (13–18W) and 1.2Ω (10–13W) come in the kit.
Is the GTL X tank prone to leaking? Its top-airflow, slide-to-fill design is built to reduce leaking during everyday use.
Can the battery be replaced? The design supports simple battery removal and recycling, though it uses a built-in 3000mAh cell rather than a standard swap-in 18650.
Vaping products contain nicotine, an addictive chemical. Intended for adults 21+ who already use nicotine.