This is the ST Racing Concepts CNC Machined Aluminum Belt Tensioner Pulley For the Associated SC10 1/10 Short Course 4x4 truck FEATURES: This pulley is made of hard anodized aluminum. INCLUDES: One pulley SPECS: Outside diameter: 11mm (7/16") Inside diameter: 7mm (9/32") flange side, 8mm (5/16") body Width: 7mm (9/32") COMMENTS: This pulley can be installed on Associated SC10 4x4 RockStar-Makita 2.4GHz RTR (ASCD9007) Associated SC10 4x4 Team Short Course Kit (ASCC9004) Associated SC10 4x4 Pro Comp 2.4GHz RTR (ASCD9006) 10/10/12 phijwa