Item Type: Roller TrolleyMaterial: Stainless Steel, Aluminum Alloy, NylonSuitable Scene: Indoor, Bathroom, Kitchen, BalconyPackage List1 x Roller Trolley1 x Load Bearing Pulley 2 x Toggle Fastener 1 x Lower Limit Positioning 1 x Fixed Screw Pack 1 x Adjustment Wrench 1 x ManualPlease purchase the corresponding size of the applicable rail separately according to the pulley.1High Strength: This stroller assembly middle support is made of solid steel, which is high strength and impact resistant and galvanized zinc plated for rust resistance. 2Stable Operation: The wheel trolley case is mounted with standard deep groove ball bearings, which are very sleek and noiseless when in use. Welded bearing positioning ensures working stability. 3Impact Resistant Head: In order to prevent strong impacts from damaging the wheels, the trolley assembly has been thickened with impact resistant parts. 4Multi Layer Plating: This cart assembly utilizes multi layer plating to provide effective protection to the wheels and increase the acid, alkali and erosion resistance of the wheels. 5L Shaped Removable Insert Design: This trolley assembly is designed with L shaped removable inserts for quick installation and easy removal.