The PROX Steel Valve Kit is crafted from top-quality nitrided steel and micro-hardened to reduce friction and wear. This ensures a longer lifespan than original valves, making it the perfect replacement for short-lived titanium valves. The kit includes a specially weight-optimized set of steel valve springs made of chrome-vanadium for extra-high RPM resistance, all of which can be installed without modifying original parts. Ideal for Yamaha motorcycles, this steel valve kit provides enhanced durability and performance.