The Uwell Nunchaku coils feature a clapton wire heating element to provide astounding flavor output. Available in two different resistance options, the 0.25O coils are designed to work best between 40 watts to 50 watts while the 0.4O coils work best between 45 to 55 watts. Uwell has stripped the idea of a threaded coil and introduced a plug-pull system where the coils are simply press fit into the atomizer base, removing any instances of cross threading or damage to the coils. This is 0.4ohm Clapton Wire Coils Plug-Pull Design Threadless Coils Organic Cotton Wick Brand: Uwell Compatible with UWELL Nunchaku Resistance 0.4ohm Wattage Range 45-55W Quantity 4