Specification Brand : XTevu BulletPoint1 : Metal linear bearing rail and blocks with pre-drilled holes for ease of mounting. BulletPoint2 : Dura ble construction for long-lasting performance. BulletPoint3 : Can be used in automatic industry machines such as robot, calculator, automatic recorder, accurate printer, etc. BulletPoint4 : This set included 2pcs SBR12-500mm Linear Bearing Rail and 4pcs SBR12UU Block Bearing. BulletPoint5 : This linear bearing is Dura ble and sturdy, which can prolong the transmission life span of your machines. Color : #736 IncludedComponents : No ItemName : Linear Rail,2PCS SBR12 500mm 12MM Linear Bearing Rail Slide Guide Shaft with 4PCS SBR12UU Slide Bearing Block ItemPackageDimensions_Height : 7 centimeters ItemPackageDimensions_Length : 55 centimeters ItemPackageDimensions_Width : 7 centimeters ItemTypeKeyword : slide-rails Manufacturer : XTevu ModelName : XTevuh528yinxsd ModelNumber : XTevuh528yinxsd NumberOfItems : 1 PartNumber : XTevuh528yinxsd ProductDescription : Features: Metal linear bearing rail and blocks with pre-drilled holes for ease of mounting. Dura ble construction for long-lasting performance. Can be used in automatic industry machines such as robot, calculator, automatic recorder, accurate printer, etc. This set included 2pcs SBR12-500mm Linear Bearing Rail and 4pcs SBR12UU Block Bearing. This linear bearing is Dura ble and sturdy, which can prolong the transmission life span of your machines.