The terminal box is designed to use 10,12, and 14 awg NM and in doing so is able to handle 30 amps, and the buss bars don't even get warm. The integrated wire clamps are designed to withstand a veritcal pull of 60 lbs, the same as the clamps on any U.L. approved junction box. Has anyone had to put 5 or more #12 together with wire nuts? A few OHM's makes a lot of heat and the terminal box makes perfect connections every time. Someone mentioned it looks like it came from the 70's, well if you think about the type of wiring that was done at that time the terminal box is a perfect replacement.