Features STABLE AND SAFE: Trolley assembly using welded bearing and pin of 4 bearing, more stable, safe use NOISELESS BEARINGS: Trolley assembly uses deep groove ball bearings to ensure that you can operate smoothly without any noise LOAD BEARING AND IMPACT RESISTANT: Each four wheeled trolley assembly has a design load of 550lb. The roller trolley assembly is made of impact resistant solid alloy steel CORROSION RESISTANT ALLOY STEEL: U shaped pulley assembly is made of solid alloy steel with high strength, corrosion resistance and easy cleaning WIDELY USED: Trolley assembly can be used in home trolley doors, wardrobe cabinets, large iron doors, curtains, automatic equipment pulley assembly, factory track pulleys Specification: Item Type: Trolley Assembly Material: Alloy steel Color: Silver Application: Used for household movable door, wardrobe, large iron door, curtain, automatic equipment pulley assembly, factory track pulley Package List:1 x Trolley Assembly Package List 1 x Trolley Assembly