Package: 4pcs Black Rubber Vibration Isolator Mounts Shock Absorber and 8pcs M6 nuts. Size: Total length is 2"(51mm),20 x 15mm (Dx H) rubber mount with M6 x 19mm Studs. Material: The rubber shock absorber's metal and rubber are bonded together using a special process. Function: protect the normal state of the equipment and obtain a good working environment. The effect of damping and noise reduction is very obvious. Application: mainly used for enginers, gasoline engines, water pumps ,Welding machine and other equipments as a damping element.