Deep groove ball bearings, fashionable, flexible sliding. The product is an outer ring with U-shaped groove pulley bearings, compression wear. Each can load 79 kg, to use and long service life. Suitable for furniture hardware accessories, door and window pulleys. Weight: 41g/set Color: Orange Material: Plastic + Bearing Steel Size: 0.6 x 3 x 1.3 cm / 0.24 x 1.18 x 0.51 inch (ID x OD x T) Inner Diameter: 6MM Outer Diameter: 30MM Thickness: 13MM Package Content: 80 x Bearing Pulley Wheel Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.