The PROX Steel Valve Kit, crafted by PROX, features top-quality nitrided steel that has been micro-hardened to reduce friction and wear. This results in longer durability compared to original valves, making it an ideal replacement for short-lived titanium valves. The kit includes a specially weight-optimized steel valve spring set made from chrome-vanadium, providing extra high RPM resilience. It can be installed without any modifications to the original parts!