High Quality Pulley: The pulley is made of anti-rust bearing and nylon body. Heavy-duty U-shaped grapple shackles feature heavy-duty heat-treated construction for durability and reliability. Ergonomic design: 90mm pulley with ball bearing, 360 degree swivel ring on the top to avoid knots of rope, cable, wire. Silent steel pulley: simple and practical pulley that works without additional noise. Easy operation and maintenance, high working efficiency. WIDE USE: This bottle holder kit is suitable for cable machines, tension machines, fitness pulley systems, clothesline accessories , garages, etc.