These are the official Kanger replacement coils for the Kanger Protank 1 and 2 , Evod , and Mini Protank 1 and 2. These are 1.5, 1.8, 2.2, and 2.5 ohms and sold in a 5 pack. The coils have been updated to a Single Organic Cotton Coil (SOCC) made with Japanese cotton and no longer utilize a silica wick. Each coil needs to be primed for 30 seconds before use. This allows the e-liquid to soak in the coils.