TEN-HIGH Linear Rail CNC parts SBR12 12mm, 1000mm 39.37inch Fully Supported Linear Rail+2pcs SBR12UU BlockBearing Block Bearing The material is made by the 45# high quality steel and case hardened,which extends the service life of the shaft and the machine. Very high load carrying capacity High stiffness and accuracy Smooth and ultra quiet bearings for rails Compact design and easy to mount and dismount.