All steel construction. High carbon, hardened steel working parts. Patented jam-proof mechanisms, precision locked rear loading, a retractable striking edge and specially designed power grip handle. Finished in durable chrome plating to withstand the bumps and scratches of daily use. Uses four No. T-50 staples sizes 1/4 in 5/16 in 3/8 in and 1/2 in Rental.