1. Ball Transfer Unit are omni-directional load-bearing spherical balls mounted inside a restraining fixture.2. 360 universal transfer bearings is suitable for curved work created on band saws and router tables.3. Ball Transfer Unit is perfect replacement for your broken one on your office chair.4. APPLICATION: Widely used in transmission system, feeding system, processing system, processing machinery.5. NOTE: Two screw holes in each bearing,screws are not included here.Specifications:Product Name: Ball Transfer UnitFEATURES: 360 degree universal transfer bearing.Model: -16BCapacity(Max.): 15kg/33.07lbBall Diameter: 5/8-inchDimension: 45 x 19mm/1.8-inch x 0.75-inch(Max.D*H)Mount Hole Dia.: 4mm/0.16-inchMount Hole Distance: 30mm/1.2-inchColour:SilverMaterial:Carbon steelPackage Contents:5 * Ball Transfer BearingOnly 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.