Features: This linear rail and block are small in size and lightweight, especially suitable for small equipments. Adopting 4-point contact design, it can bear load from every direction, and has good strength and high accuracy. Designed with ball retainer, which allows interchangeability in the case of small precision. Block has lubrication system; lubrication oil can be easily put into the oil inlet on the side. Widely used for automatic equipment, precision measuring equipment, and many other machines that need precision linear movement. Specification: Model: MGN12(linear rail), MGN12B(slide block) Type: Slide rail Slide Track: Linear rail Rail Length: 300mm / 11.8in Rail Width: 12mm / 0.5in Material: Bearing steel Block Fixation Method: Locked Weight: 269g / 9.5oz (approx.) Package List: 1 * Linear Guide Rail 2 * Linear Guide Blocks Note: Please allow small size error due to manual measurement. Thanks for your understanding.