Specifications:Type: Bolt-fixingMaterial(Bearing Ball): Carbon SteelLoad Capacity(Max.): 30kg / 66lbBall Diameter: 24mm / 0.94 InchThread Size: M8X22mm / M8x0.87 Inch(DxL)Body Size: 31x31mm / 1.22x1.22 Inch(DxH)Features:1. Ball Transfer Unit is omni-directional load-bearing spherical balls mounted inside a restraining fixture2. 360 degree universal transfer bearing ball is good for facilitating smooth, multi-directional motion3. Widely used in various transmission systems, feed systems, processing systems, packaging machinery auxiliary equipment, as well as object turning and confluence. Note: 1. Use for transporting stuff has a smooth or flat bottom2. If to transport something that has an uneven or soft bottom surface, the tray could help you3. This ball transfer unit is not used as a swivel caster to move on the floorPackage Content:6 x Ball Transfer Unit