This linear rail kit includes 2pcs 7.87 inch / 200mm length linear rail shafts, shaft diameter 0.47 inch/ 12mm and 4 SBR12UU slider blocks We provide customization, including the rail length, End stops which avoid the blocks sliding off the end of the rail, and the Handle which used to adjust the tightness of the slider block, you can see the real object of the retaining ring and handle in the 2nd image. You can let us know your need through Amazon Message The maximum weight of single SBR12 UU slider block can carry is 94.4lbs, 4Pcs SBR12 UU slider blocks are 377.6lbs. You can get more technical data from the images The material of shaft is the Carbon Steel with Chromium coating, quenching and anti-rust treatment; high hardness, more durable. Industrial-grade standard SBR block, with a high precision linear bearing inside. Make the sliding smooth, low friction, silent operation If this item is not FBA, the lead time is 7-10 Business Days except for for Chinese National Day holiday and Spring Festival Specifications
Brand: Mssoomm
Model: SBR12
Shaft Diameter: 12mm
This item includes:
2pcs SBR12-7.87 inch / 200mm Linear Slide Guide Fully-supported Rails
4pcs SBR12UU Bearing Blocks

Feature & Application:
1. Cylindrical guide composed by principal rail and aluminum support, stabilizing the original rail.
2. Sliding blocks to be used cooperatively with rails, smooth sliding provided by inside linear bearing.
3. The cnc linear rails apply for various kinds of automated machines and equipment, can help build economical linear guiding systems.
Applicable for large-scale transmission equipment including industrial robots, cleaning equipment and supporting devices, etc.

Please Note:
We provide customization, including the rail length, Retaining ring which used to stop the blocks from sliding off the end of the rail, and the Handle which used to adjust the tightness of the slider.
You can see the real object of the retaining ring and handle in the 2nd image. You can let us know your need through Amazon Message, pls contact us.