Replacement Coil Head Description The TFV12 Prince Tank M4 coils are quadruple coil heads. The coils feature a 12 point wicking system for quick cotton saturation to help prevent dry hits even when chain-vaping and to assist with heat dissipation. The coil features a 0.17-ohm resistance and a wattage rating of 30-70 watts, however, SMOK recommends operating the coil at 45-55 watts. The M4 coil is designed to be used primarily with the SMOK Stick Prince Starter Kit. Includes three (3) TFV12 Prince X6 replacement coil heads.