Team Associated 12mm Aluminum Rear Clamping Wheel Hex Set, and is intended for use with the Team Associated B4.1 and B44.1 1/10 scale buggies. Team Associated's Factory Team Aluminum 12mm Clamping Wheel Hexes clamp securely onto the axle, preventing the hex from getting stuck in your wheels, which allows for speedy wheel changes. The hex adaptors are CNC machined out of 6061-T6 Aluminum and anodized Factory Team blue. The 12mm hexes use a 2-56 Socket Head Cap screw (included), which allows for the use of either a 5/64" or 2mm Allen wrench.