The Steck Manufacturing Hold-a-Rotor Tool Kit, No. STC71000, is designed to hold automotive and light truck disc brake rotors in place. The kit comes with a green plug that fits 12mm wheel mounting studs and a red plug that fits 14mm studs. The plugs are made from a super-duty durable polymer for oil and grease resistance and are made in the USA. Each plug easily slips on and off studs one-handed to secure the rotor to the hub face.