Features This linear slide rail shaft is made of high quality carbon steel, and the bearing block is made of aluminum alloy, sturdy and durable. Industrial-grade standard SBR block with high precision. The system works beautifully for both slider motion as well as panning Aluminum alloy support rail with pre-drilled holes for ease of mounting. This kind of linear rail shaft is perfect for your DIY CNC routers, mills, lathes. Descriptions: The linear slide rail shaft is made of high quality carbon steel, and the bearing block is made of aluminum alloy, sturdy and durable. Perfect for your DIY CNC routers, no more unwanted errors in your machining work mills, lathes. Features: This linear slide rail shaft is made of high quality carbon steel, and the bearing block is made of aluminum alloy, sturdy and durable. Industrial-grade standard SBR block with high precision. The system works beautifully for both slider motion as well as panning Aluminum alloy support rail with pre-drilled holes for ease of mounting. This kind of linear rail shaft is perfect for your DIY CNC routers, mills, lathes. Specifications: Material: high carbon steel, aluminum alloy Model: SBR12 Color: Silver Rail shaft length: 200mm/7.87inch Rail shaft diameter: 30mm/1.18inch Bearing Block size: 40*40*26mm/1.57*1.57*1.02in Weight: 991g Package Included: 2 x Linear Slide Rail Shaft 4 x Bearing Block Package List