CNC Aluminum 48P 87T Spur Gear for use on the Associated SC10, B4 and T4Vehicles. FEATURES: CNC Aluminum construction Hard Anodized color YOU WILLRECEIVE: One 48 Pitch 87 Tooth Spur Gear REQUIREMENTS: Installation on thevehicle SPECIFICATIONS: Outer diameter: 47mm (1.85 ) Inner diameter: 4.8mm(.189 ) Teeth count: 87 teeth.