These Power Crown heavy-duty staples are made of steel and come in silver. They have a 9/16-inch leg length, a 7/16-inch crown width, and a fit wire diameter of 0.050 x 0.019 inches. There are 4000 staples in a pack. The staples are suitable for the T6-8, T6-80C2, USO56-1, and PC4000-OC2 stapler.