Deep groove ball bearings, fashionable, slide flexible.The product is outer ring with U-shaped groove pulley bearings,compression wear.Each can load 79kg,good to use and long service life.Suitable for furniture hardware accessories,Doors and windows pulley.Weight: 123gcolour:OrangeMaterial:Plastic + bearing steelSize:0.6 x 3 x 1.3cm/0.24 x 1.18 x 0.51 inch(ID x OD x T)Inside Diameter: 6MMOutside diameter: 30MMThickness: 13MMPackage Contents:12 x Bearing Pulley WheelOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.