1up Racing Carbon Fiber Body Hole Protectors 6mm size common on 1/10 Touring Cars 5mm size common on 1/10 Off-Road and 1/12 On-Road 7-8mm size common on 1/5-1/8 On-Road 1/8 Off-Road size fits posts up to 8mm thick and features 2 elongated CF washers to allow for chassis flex.