Specification Brand : Iverntech BulletPoint1 : Surface technology: Anti-oxidation by electroplating (nickel plating) BulletPoint2 : Rail guide material: bearing steel. Rail guide length: 300mm BulletPoint3 : Block: MGN12H ball bearing carriage. Block material: Stainless Steel. Blocks are pre-loaded BulletPoint4 : Suggested to use M3 T nut and screws if you fix it to 20 series EU Al-profile BulletPoint5 : There are two rubber stoppers on each side of the linear rail, it can prevent the carriage block from falling out, pls contact with us if you have any products questions, we will try our best to deal with it. Color : Silver ExternallyAssignedProductIdentifier1 : 732140825037 ExternallyAssignedProductIdentifier2 : 0732140825037 FinishType : Polished ItemName : Iverntech MGN12 300mm Linear Rail Guide with MGN12H Stainless Steel Carriage Block for Ender 3, Corexy, Tronxy, Delta Kossel 3D Printers Upgrades and CNC Machine ItemPackageDimensions_Height : 32.5882 centimeters ItemPackageDimensions_Length : 4.191 centimeters ItemPackageDimensions_Width : 4.5974 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : linear-motion-guides Manufacturer : Iverntech Material : Alloy Steel Material1 : Aluminum Material2 : Zinc ModelNumber : IT-RD048-370 NumberOfItems : 1 PartNumber : AW013 ProductDescription : Packing list: 1x 300mm MGN12 Rail Guide + MGN12H Carriage ProductSiteLaunchDate : 2017-09-30T07:00:00.000Z Size : 300MM Style : Green SupplierDeclaredDgHzRegulation : not_applicable UnspscCode : 24102000