Specification Brand : ReliaBot BulletPoint1 : MGN12H carriage block for MGN12(MR12) linear rail BulletPoint2 : Size: 45.7*27*10mm; the distance of the center of the threaded holes: 20*20mm BulletPoint3 : Threaded holes: 4-M3*3.5 BulletPoint4 : Been installed on the plastic rail in case of losing the steel balls. Align the plastic rail with the rail to which the carriage block needs to be added, and then move the carriage block onto the rail, to prevent the steel balls from falling during installation. BulletPoint5 : Come with 2 spare steel balls in the package for backup Color : Black ExternallyAssignedProductIdentifier1 : 190459827232 ExternallyAssignedProductIdentifier2 : 0190459827232 ItemName : ReliaBot MGN12H Carriage Block for 12mm Wide MGN12 Linear Rail Guide ItemPackageDimensions_Height : 8 centimeters ItemPackageDimensions_Length : 1.3 centimeters ItemPackageDimensions_Width : 6.8 centimeters ItemTypeKeyword : linear-motion-guides Manufacturer : ReliaBot Material : aluminum Material1 : Plastic Material2 : Steel Material3 : Steel NumberOfBoxes : 1 NumberOfItems : 6 PackageLevel : unit PartNumber : 2040V-1500MM ProductDescription : This block is suitable for ReliaBot and Iverntech MGN12 rails, but may not be suitable for other suppliers'. Packing list: 1 * MGN12H carriage block(been installed on the fake rail) 2 * steel balls(for backup) ProductSiteLaunchDate : 2020-03-18T12:32:16.571Z Size : MGN12H Block Style : Carriage Block SupplierDeclaredDgHzRegulation : not_applicable UnspscCode : 24102000