Standard Sizes: For the 150 model and 120 model , the inner diameter round hole of the upper pressing plate is 14mm and the lower pressing plate is 16mm . The diameter of the 150 model is 41mm and the 125 model is 39mm . Standard sizes facilitate your selection and are more suitable​ Simple Installation: Please cut off the power supply before installation and move the grinding wheel . When installing the lower pressing plate , place it under the grinding head first and then pull it up gradually until it contacts the workpiece​ Effective Improvement of Grinding and Safety: Correct use of the angle grinder lower pressing plate can effectively improve grinding efficiency and safety , reducing wear and failure rates​ Humanized Design: Our designed pressing plate is more in line with ergonomic design , which makes using safer and more comfortable and reduces the possibility of human using errors Premium Material Properties: This product adopts iron which features good thermal conductivity , high strength , plasticity , strong magnetism and important effects on human health​, Weight: 1.433004703 pounds, Manufacturer: Sutowe