Reverse pull headgear, also known as a "facemask", is a semi-custom appliance. This appliance is pre-made and is adjusted to fit on the patients face. The appliance has pads that can usually be adjusted to fit comfortably on the forehead and chin by moving them either up or down. In addition, there is a bar in the middle where there are elastics placed. The bar can also be moved up or down is usually placed near the bottom of the front teeth. The appliance is worn by attaching elastics from the bar to a splint, or braces, attached to the upper jaw. The elastics provide the traction to pull the upper jaw forward and modify the growth of the upper jaw. The size of the elastic used is usually around 6 ounces per side. Together, both elastics place a 12 ounce force on the upper jaw to grow forward.