These are the optional Rear Sponge Tires for use on the Tamiya F104 Chassis Vehicles. FEATURES: Sponge construction Black in color INCLUDES: Two Rear Sponge Tires REQUIRES: Installation on Wheels SPECS: Outer Diameter: 62mm (2.4") Inner Diameter: 42mm (1.7") Width: 35.75mm (1.4") cnh 9/30/09 ir/jxs