1,Impact resistant, stamped steel frame, gear case and cover for durability and light weight. 2,Hardened steel load sharing gears. 3,Double pawl arrangement for assured load control. 4,Two chain guide rollers for positive chain engagement. 5, Weston type braking system for positive load control and positioning. 6,Simple one-handed, free chaining for fast load attachment 7,Minimal maintenance with no special tools required.--Wu Zhou power tools