Product Description: Advantages: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information 2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed.3.Made of bearing steel and long lasting performance.4.It has good wear resistance and strength, low friction coefficients and long usage spans.5.Widely use in semiconductor manufacturing equipment, printed circuit boards, IC assembly equipment, robotic arms, precision measurement machine and other small linear motion device. Specifications:Material: Bearing SteelColor: multicolorSize: Overall Dimensions: 20x2.7x1.3cm/7.87x1.06x0.51inch(LxWxH)Slider Width: 2.7cm/1.06inchGuide Rail Width: 1.2cm/0.47inchGuide Rail Thickness: 0.8cm/0.31inchBore Diameter: 0.6cm/0.23inchPitch of Holes: 2.5cm/0.98inchSlider Length: 20cm/7.87inchWeight:400g Package include:4 x MGN12 Guide Rail Sliding Blocks2 x Linear Sliding Guide