1This linear rail and block are small in size and lightweight, especially suitable for small equipments. 2Adopting 4-point contact design, it can bear load from every direction, and has good strength and high accuracy. 3Designed with ball retainer, which allows interchangeability in the case of small precision. 4Block has lubrication system; lubrication oil can be easily put into the oil inlet on the side. 5Widely used for automatic equipment, precision measuring equipment, and many other machines that need precision linear movement. 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 railSlide Track: Linear railRail Length: 450mm / 17.7inRailWidth: 12mm / 0.5in Material: Bearing steel Block Fixation Method: Locked Weight: 371g / 13.1oz (approx.)Package List:1 * Linear Guide Rail2 * Linear Guide BlocksNote: Please allow small size error due to manual measurement. Thanks for your understanding.