Linear motion ball bearing bushing and linear rubber seal. Perfect for linear motion on 3D printers, CNC and other applications. Ball bearings with two rubber seals sealed to prevent the ingress of dirt, and foreign matter. Smooth movement, low friction, high rigidity and long service life. Economical, easy to maintain, replace. Product Name: Linear Bearing Material: Bearing Steel Color: Silver Weight: 337g Model: LM20UU Outer Diameter: 32mm Inner Diameter: 20mm Length: 42mm Package Content: 4 pcs x Linear Bearing Only the above package content, Other products are not included. Note: Light shooting 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 +/- 1-3 cm.