The Smok TFV12 Q4 replacement coils shipped in packs of 3 are for use with the Smok TFV12 Prince tank and come in a resistance of 0.4Ω and are for use between the wattage range of 40W - 100W (Best: 60W - 80W). Available in Q4 (0.4Ω), X6 (0.15Ω), T10 (0.12Ω) and M4 (0.17Ω)