Application:3D PrintersCNC EngraversHot ire MachinesLaser Engraving MachineCamera SlidersPlasma CuttersRoboticsFurnitureWoodworking DIYAnd much moreMaterial:aluminiumDiameter: 16mm 20mm 25mm 30mm Model: TBR16UU TBR20UU TBR25UU TBR30UU Package Included:1pcsNote :This product supports customization, if there is no length you need, please touch me, I can customise any size you want for you