# Eleaf coils, a guide to the EC, GTL, GX and HW series > Eleaf coils explained, from EC, GTL and GS Air to GX, EN, EP and HW, with how to read the code, which tank each series fits and the right wattage. Every generation of Eleaf tank has come with its own replacement head. The result is a shop page that can line up thirty references under one brand name, from the EC2 to the HW-T by way of the GTL and the GS-A. For anyone shopping for **Eleaf coils**, the device name is no longer enough. You need to read the code printed on the box, then pick the resistance that suits your draw. ## Eleaf coils, the short answer The letters at the start of the code name the platform, meaning the shape and diameter of the head. **Eleaf coils** only fit the devices built for their platform, whatever their resistance in ohms. The EC series goes in the Melo tanks, the GTL in the GTL pod tanks and tanks as well as the iSolo Air 3 and the iJust P40, the GS Air in the GS Air tanks, the GZ in the GZeno S, the EN in the EN Air and EN Drive, the GX in the GX Tank, the EP in the iJust AIO Pro, the EF in the Pesso and the HW in the Ello family. Letters added after the hyphen (EC-A, EC2-M, GS-A, HW-T) mark a variant of the same platform, with a different material or structure. ## Reading the code on Eleaf coils A full reference holds three pieces of information, all printed on the box. Reading them in order heads off many wasted purchases. ### The code first, then the resistance The code comes first, because it decides the fit. The resistance comes next and points to the draw. On most of its product pages, Eleaf rates its 1.2 ohm heads for mouth-to-lung (MTL), its 0.6 to 0.8 ohm heads for restricted direct lung (RDL) and its 0.15 to 0.5 ohm heads for direct lung (DL). The EP 1.2 ohm is listed for MTL, the EP 0.6 ohm for RDL and the EP 0.15 ohm for DL. The GZ 0.8 ohm is the exception, rated for MTL. ### The wire material Three materials run through the current range, plus the SS316L stainless mesh of the EC head supplied with the Melo 5. Kanthal is used on several of the heads covered here (GTL, GZ, EP, EF, HW-M). NiCr appears on the GT 1.2 ohm. AST, short for "All-Time Stable", is an austenitic stainless steel that Eleaf uses on the EC-A, GS-A, GX and two values of the EN series, and its pages credit it with even heating and a longer lifespan. ## Eleaf coil platforms, device by device Each platform belongs to a generation of hardware. The detail below follows the manufacturer's own pages for each head and each device. ### EC, the Melo family This is one of the most varied platforms in the range. The EC2 was introduced with the Melo 4, the EC-M mesh head at 0.15 ohm came with the iStick Pico X and that same Melo 4, and the AST EC-A (0.15, 0.3 and 0.5 ohm) fits the Melo 4S and the Melo 6. The Melo C takes the EC2-M 0.3 ohm and the EC2 0.5 ohm, and the Melo X page states that it works with all EC coils. ### GTL and GT, two platforms not to mix up The GTL is found in the GTL Pod Tank, the GTL D20, the GTL X Tank, the iSolo Air 3 and the iJust P40, from 0.3 to 1.2 ohm depending on the device. The GTL X also accepts the GTL-D, a version with a reworked wick. The GT serves the iJust Mini (GT 1.2 ohm in NiCr) and the iJust AIO (GT M 0.6 ohm). Eleaf states that the GTL has a larger diameter than the GT, so despite the similar name, one does not replace the other. ### GS Air, GZ and EN, the tight-draw tanks The GS Air 4 takes every GS Air head, including the GS Air 1.4 ohm (Kanthal mesh, 6 to 12 W) and the GS-A 0.8 ohm (AST, 8 to 15 W). The GZ pushes into the GZeno S without a thread, at 0.4, 0.8 or 1.2 ohm. The EN Air is designed for MTL with EN heads at 0.8 and 1.2 ohm, and the EN Drive ships with an EN 0.6 ohm and accepts the other two values. ### GX, EP, EF and HW, the direct lung heads The GX Tank runs on the GX 0.2 ohm (dual mesh, 50 to 80 W) or 0.5 ohm (25 to 45 W). The iJust AIO Pro takes the EP series, and the Pesso takes the EF 0.3 ohm and the EF-M 0.6 ohm, two thread-free heads that you change by pulling out the old one and pushing in the new. The HW heads fit the Ello family, with the HW-M 0.15 ohm (50 to 100 W) and the HW-T 0.2 ohm, whose head holds a small propeller that swirls the air around the mesh. ## Eleaf coil compatibility table Wattage ranges come from each head's product page. Where several values exist, the table gives the ones the manufacturer details. | Series | Devices named by Eleaf | Values and ranges | |---|---|---| | EC-A | Melo 4S, Melo 6 | 0.15 ohm (40-70 W), 0.3 ohm (30-50 W), 0.5 ohm (20-40 W) | | EC2, EC2-M | Melo 4, Melo C | EC2 0.3 ohm (30-80 W), EC2-M 0.3 ohm (30-50 W) | | GTL | GTL Pod Tank, GTL D20, GTL X, iSolo Air 3, iJust P40 | 0.4 ohm (20-30 W), 0.8 ohm (12-18 W), 1.2 ohm (7-13 W) | | GT | iJust Mini, iJust AIO | GT 1.2 ohm, GT M 0.6 ohm | | GS Air, GS-A | GS Air tanks, including the GS Air 4 | 1.4 ohm (6-12 W), GS-A 0.8 ohm (8-15 W) | | GZ | GZeno S | 0.8 ohm (12-18 W), 1.2 ohm (7-13 W) | | EN | EN Air, EN Drive | 0.6 ohm (13-20 W), 0.8 ohm (13-18 W), 1.2 ohm (9-12 W) | | GX | GX Tank | 0.2 ohm (50-80 W), 0.5 ohm (25-45 W) | | EP | iJust AIO Pro | 0.15 ohm (55-80 W), 0.6 ohm (18-26 W), 1.2 ohm (10-15 W) | | EF | Pesso | EF 0.3 ohm (30-60 W), EF-M 0.6 ohm | | HW | Ello family | HW-M 0.15 ohm (50-100 W), HW-T 0.2 ohm | Staying inside the stated range matters as much as the code. Above it, the cotton dries faster than the liquid can soak back in, and a burnt taste can follow quickly. ## Details the shop listings leave out A few quirks of the range only show up when you cross-check the manufacturer's pages. They prevent subtler mistakes than a plain wrong code. ### Diameter, the most reliable clue Eleaf publishes the dimensions of several heads. The GS-A measures 8.5 mm across and 17 mm tall, the GZ 11 mm by 20, the EC-A 12 mm by 27 and the GX 14 mm by 26.5. Faced with a head whose code has worn off, a pair of callipers settles the question better than memory. ### Tank capacity in the UK The product pages often list two capacities for the same tank, a larger standard version and a 2 ml version. In the UK, refillable tanks are limited to 2 ml and nicotine e-liquid to 20 mg/ml in bottles of no more than 10 ml, so the 2 ml version is the one sold here. The coil platform stays the same across both, and the [guide to vape tanks](/uk/vape-tank-guide/) explains what else the limit changes. ### Dry-hit protection On the Mini iStick 2 supplied with the GS Air 4, the page says the chipset cuts output when it detects a lack of e-liquid on a GS-A head, thanks to its AST wire. The feature depends on the pairing of device and head, not on the coil alone. ## FAQ Five questions come up often when it is time to buy replacement heads for one of the brand's devices. ### How do you prime a new coil before fitting it? Put a few drops of e-liquid on the cotton visible through the side openings, then let the filled tank stand for a few minutes before the first puff. Start at the bottom of the wattage range printed on the box. ### Can a coil from another brand go in an Eleaf tank? Some makers sell heads described as compatible with an Eleaf platform, but nothing on Eleaf's own pages covers them. When in doubt, stay with the original series, whose fit and seal were designed for the tank. ### When should a coil be replaced? The usual signs are fading flavour, thinner vapour or an off taste that stays after a refill. A very sweet liquid or one high in vegetable glycerine generally clogs the wick sooner. ### Which e-liquid suits a 1.2 ohm head? A tight-draw head with small wicking holes prefers a fairly thin liquid, on the propylene glycol side. The [e-liquid guide](/uk/e-liquid-guide/) explains how to read the PG/VG ratio on the label. ### What if the device reads "no coil"? Remove the head, check that the contact pin is clean and dry, then refit it without forcing. If the message persists with a new head, the fault more likely lies with the connector or the tank than with the coil. ## Choosing Eleaf coils without picking the wrong platform The range looks crowded when read by model name, and falls into about ten platforms once you read the code. The same logic applies to a [Kangertech tank](/uk/kangertech-tank/), whose families are told apart by the coil base, and to the [Aspire range and its coils](/uk/aspire-vape-tank/). With **Eleaf coils**, the right check has three steps, the code first, then the resistance for your draw, then the wattage range. That approach works for any vaping kit with replaceable heads. This article is strictly informative and is written for adult vapers only. It is not a buying recommendation, and vaping products can contain nicotine, a substance that causes dependence. Vaping products are not for sale to anyone under 18 in the UK.