Coils for the Smok Micro TFV4.Micro-STC2 Specifications:Patented Fused Clapton Dual CoreLower Wattage & more vapor0.3Ohm (30w-60w)Micro-CLP2 Specifications:Patented Stainless Steel Dual CoreTemperature Sensing Capability0.25Ohm (30w-60w)