RPM head protector has an additional 0.100” or almost 1/8” of additional thickness on top to add extra skid and impact resistance to the fragile cooling fins of the stock Traxxas 2.5 & 2.5R heads. Additionally, our Head Guard has a positive locking system that absolutely will not allow the Head Guard to pull itself free during a crash. The RPM Head Guard is designed specifically for the Traxxas 2.5 & 2.5R stock engine head which is currently used in many Traxxas models including the Revo, Jato, T-Maxx, S-Maxx, SportMaxx, Nitro 4-Tec 2.5, & Nitro Rustler 2.5. The RPM Head Guard comes with a full set of screws as well as complete installation instructions. They are available in Black, Blue, & Dyeable Silver and are molded in our trademark blend of bulletproof nylons for strength and durability unmatched by any other material on the market!