TEMCo TH0394-1 1/4" Conduit Hole Size Knockout Punch Unit & Manual Draw Stud – (1.70" – Actual Hole Size) : Amazon.ca: Tools & Home Improvement
AMZCNC Hydraulic Knockout Punch Electrical Conduit Hole Cutter Set KO Tool (8T(1/2"-2")) : Amazon.ca: Tools & Home Improvement
Milwaukee M18 18-Volt Li-Ion 1/2 in. to 4 in. Force Logic High Capacity Cordless Knockout Tool Kit with Die Set & Fish Tape 2676-23-48-22-4195 - The Home Depot