The Subaru / Robin 20B-31601-20 Camshaft Assembly helps control the timing and movement of engine valves in compatible engines during operation. Designed as a replacement camshaft assembly, it rotates with the engine and operates the valve mechanism at the required intervals to support proper intake and exhaust cycles. A properly functioning camshaft can support smooth engine operatio... https://www.wholetoolbox.com/subaru-robin-20b-31601-20-camshaft-assembly/20B-31601-20.html