The Ferrea Audi/VW 7mm Radial Groove Valve Lock - Single is a high-performance valve lock designed specifically for Audi and Volkswagen engines. This valve lock is made from high-grade steel and features a 7mm radial groove design for maximum strength and durability. The design also helps to reduce friction and wear while providing a secure fit. This valve lock is ideal for high-performance applications and is a great way to upgrade your engine for improved performance.