SMOK TFV12 Prince Tank. The 0.4 Ohm coils are V12 Prince Q4 Quadruple coils and are suitable for an output from 40 to 100 watt (ideal performance between 60 and 80 watt). The 0.17 Ohm coils are V12 Prince M4 coils and are suitable for an output from 30 to 70 watt (ideal performance between 45 and 55 watt).