This is a set of two Traxxas Chrome Gemini 3.8" wheels for the Traxxas Revo and T-Maxx 3.3 tires. These are the same size as the 3.8" rims that come stock on the Revo and T-Maxx 3.3. No tires are included. Tires to fit these wheels are available separately. These have a standard 14mm hex, and can be used on other vehicles if you use the 3.8" tires with them. The larger diameter of these wheels compared to older monster truck wheels gives you less sidewall flex in the tire, which amounts to better handling.