two unit at one time,so it can be used recyclly,both for thick and thin type of rubber sheets. Once year later, the thickchoppers can be used to cut the thin rubber after you sharpen the knife,and the thin choppers can be used to cut thick rubber sheets. Theadvantages is saving labor force and making full use of the blades.4.adjusting the width of rubber strip through the speed controller button on the side..5.safety valve to avoid any hurt.6.efficiency stop to operate and stopthe machine immed