... manufacturing: 1. Sliding Gate Wheel, Sliding Gate Track, Sliding Gate Track Catcher. 2. Cantilever Gate Wheel, Cantilever Gate Channel, Gate End Stopper, Gate Stop, Guide Roller Bracket ... to fight against rust.4. The existing diameters come in 50mm, 58mm, 68mm, 78mm, 88mm,98mm, of couse, the custom sizes ...