HKS Adjustable Camshaft Pulleys SpecificationsChoose HKS adjustable cam pulleys for a perfect camshaft timing. Fruit of long and meticulous R&D by HKS they ensure both great performance and high reliability. When your engine specifications change (stroker kit larger turbo different camshafts...) the ideal valve timing changes too : these pulleys allow to precisely control engine timing giving you the best out of your set up.These pulleys are 10% lighter and 30% more resistant than the previous generation models from HKS thanks to new material (duralumin) and Nickel coating.