Specification Brand : ReliaBot BulletPoint1 : 300mm MGN15 linear rail with 1 MGN15C block BulletPoint2 : There are 2 red rubber stoppers or cable ties to keep the block on the rail BulletPoint3 : Please be careful when removing the block from the rail or installing the block to the rail, in case the balls in the block fall out. BulletPoint4 : Used for high load conditions BulletPoint5 : Comes with 2 or more spare balls for backup ItemName : ReliaBot 300mm MGN15 Linear Rail Guide with MGN15C Carriage Block for DLP UV 3D Printer and CNC Machine ItemPackageDimensions_Height : 33.1 centimeters ItemPackageDimensions_Length : 4.8 centimeters ItemPackageDimensions_Width : 5.2 centimeters ItemTypeKeyword : linear-motion-guides Manufacturer : ReliaBot Material : Steel ModelNumber : RZ008-300c NumberOfItems : 1 PartNumber : RZ008-300c ProductDescription : Packing list: 1 * 300mm MGN15 linear rail 1 * MGN15C carriage block 2 * steel balls for backup ProductSiteLaunchDate : 2019-07-12T07:00:00.000Z Size : MGN15 Style : 300mm+MGN15C UnspscCode : 24102000