Model: Horizontal (as pics) Material: Aluminium alloy Size: 8mm to 50mm / SHF8 ~ SHF50 (You can select the required specification and size, buy it now.) Packing quantity:2 Mainly used for the linear axis up, both sides of the wall can be bolted in machinery. so that the linear bearing or slider, in axis movement back and forth, and complete mechanical function. Rust protection,acid-resisting, Easy to install and use. If there is anything you need, Please contact with us. There are a variety of Model and size available but they are not all listed.