Features:Material: Made of high-quality metal + nylon, strong and durable.Style: There are 4 styles for you to choose from, choose the corresponding specifications according to your needs.Carrying capacity: durable and load-bearing.Features: Thicker metal iron for shell, higher hardness and for stronger load-bearing capacity.Application: used for track reversal, rolling gate, sliding door, industrial machinery, wire rope guide rail device, container rack, baby door, dog door, etc. Package Includes:1x Sliding Door Roller Kit Specifications:Material: MetalWeight: 42g/32gSize: 41mm/1.61inchType: Double Convex Wheel/Double Groove Wheel/Single Convex Wheel/Single Groove Wheel(optional) note:1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.