The PROX Steel Valve Kit is engineered to the highest standards using nitrited steel that has undergone micro-hardening processes to significantly reduce friction and wear. These valves offer longer durability compared to original manufacturer valves and are an ideal replacement for short-lived titanium valves. Includes a specially calibrated set of chrome-vanadium steel valve springs designed to withstand extremely high RPMs. The kit can be installed without making any changes to the original parts, ensuring a perfect and seamless fit.