Greenlee Manual Round Standard Knockout Punch Kits, 1/2 - 1 1/4 in - 1 ST (332-735BB)" - Walmart.com
Greenlee® Slug-Buster® 7238SB Manual Knockout Punch Die Kit, 10 ga Capacity, For Use With Battery Powered/Hydraulic Ratchet Driver and 3/8 in and 3/4 in Draw Stud, 1/2 to 2 in Conduit/Pipe, Mild Steel
Greenlee Intelli-Punch 11-Ton Knockout Driver - Pro Tool Reviews
Knockout Set for Hydraulic Drivers with Standard Round 2-1/2" to 4" | Greenlee