Alright, for all you electricians and contractors out there - this TEMCo conduit punch and die is exactly what you need for clean, professional holes. Here's the important part: it's sized for conduit measurements, NOT the actual hole size. So this 4\ punch will make a hole about 4.5\ across, which is perfect for 4\ conduit tubing. It works with any knock out punch set that uses the standard 3/4\-16 thread (including TEMCo, Greenlee, and others). This thing can handle up to 13 US tons of punching force and works on steel up to 1/8\ thick or stainless steel up to 1/16\. Made from hardened tool steel with a black oxide finish, it'll punch through steel, stainless, brass, copper, aluminum, fiberglass, plastic - you name it. Just remember it's not for super hard alloys like 7075 aluminum. If you're tired of messy conduit holes, this set will make your job way easier and give you that clean, professional finish every time.