The Brian Crower Honda/Acura 5.5mm Valve Stem Keepers are essential components for ensuring proper valve function in high-performance engines. Known as valve keepers, valve keys, or valve retainers, these small yet crucial steel/high carbon components snap into a notch in the end of a valve stem. Sold in packs of 32, these valve stem keepers are designed to fit 5.5mm valve stems, providing a precise and secure fit for optimal performance. Also compatible with other aftermarket valves, they offer versatility for various engine builds. Fastening the valve stem, valve spring, and retaining washer together ensure smooth and reliable operation within the engine.