1、STABLE AND SAFE: Trolley assembly using welded bearing and pin of 4 bearing, more stable, safe use 2、NOISELESS BEARINGS: Trolley assembly uses deep groove ball bearings to ensure that you can operate smoothly without any noise 3、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 4、CORROSION RESISTANT ALLOY STEEL: U shaped pulley assembly is made of solid alloy steel with high strength, corrosion resistance and easy cleaning 5、WIDELY USED: Trolley assembly can be used in home trolley doors, wardrobe cabinets, large iron doors, curtains, automatic equipment pulley assembly, factory track pulleys 1 x Trolley Assembly Item Type: Trolley AssemblyMaterial: Alloy steelColor: SilverApplication: Used for household movable door, wardrobe, large iron door, curtain, automatic equipment pulley assembly, factory track pulley Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.