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" 5/16" 3/8" And 1/2". Rental.