Rapid Adjust Buckles are one hand buckles for upper-extremity harnesses for voluntary closing terminal devices. These buckles may replace any three or four bar buckles and most metal belt or latch type buckles used in orthotic braces. The buckle locks positively into place anywhere on dacron/nylon or pro-poly web tape. The buckles are made of nylon. SIZES: Large, for one-inch wide webbing; Medium for three-quarter inch wide webbing. COLOR: White.