Features:This linear rail and block are small in size andlightweight, especially suitable for small equipments. Adopting 4-point contact design, it canbear load from every direction, and has good strength and high accuracy. Designed with ball retainer, which allowsinterchangeability in the case of small precision. Block has lubrication system; lubrication oil canbe easily put into the oil inlet on the side. Widely used for automatic equipment,precision measuring equipment, and many other machines that need precisionlinear movement. Specifications:Model: LML7B Type: Slide rail Slide Track: Linear rail Length: 40mm/1.6in, 55mm/2.2in, 70mm/2.8in (Optional) Width: 7mm/0.5inMaterial: Bearing steelAccuracy Class: HBlock Fixation Method: LockedWeight: 19g~27g(approx.) Package Includes:1 x Linear Guide Rail 1 x Linear Guide Block Note: Please allow small size error due to manual measurement. Thanks for your understanding..