The Uwell Nunchaku Replacement Coils are claptionized A1 vertically coils with organic cotton suitable for the Uwell Nunchaku Tank. The Nunchaku Tank Replacement Coils comes in packs of 4 replacement coils and are available in 0.25ohm and 0.4ohm. The 0.25 Nunchaku Replacement Coil uses a claptionized A1 coil rated for 40-50 watts while the 0.4 Nunchaku Replacement Coil uses a claptionized A1 coil rated for 45-55 watts.