... U shape brake tooth" technique, its action is safe and reliable.2. Brake system utilizing special material, special fabrication ... processing, and it is anti corrosive, shockproof and wearproof. 3. One step shaping Aluminmun alloy shell, and it is light, ... 1m/sec. 7. Material: aero-wires, special spliced sling,and it is feature flame retardant, heat resisting, anti corrosive, ...