The MF-12 welds BDEP, CTC, SSP, CP, FTC, PN or LN type fasteners to ductwork up to 20 gauge. It requires 220 volt, 50 to 60 hz service fused for 30 amps. Place a pin on the magnetic tip. Insert the pin through the insulation, give the pin a 1/4 twist, and depress the trigger switch. For LN type fasteners use a TPL2 tip. For PN type fasteners use a TP2 tip.