Skunk2 Alpha Series Honda/Acura Stock Size H Series Valve Set (Standard Compression)Skunk2 Alpha Series valves are manufactured from HNV3 martensitic steel (IN) and EV8 austenitic steel (EX) one piece forgings, each valve is heat treated using a proprietary process for extraordinary strength and durability. Alpha Series Valves feature hard chrome plating and fully machined valve heads. Other valves may appear similar, but only Alpha Series Valves feature specially designed valve head profiles to optimize airflow. Skunk2 designs,