This is the replacement Heatsink Cylinder Head for the O.S. 50 SX-H Ring Hyper. This will also fit on the standard 50 SX-H Ring FEATURES: Aluminum construction, blue in color INCLUDES: One hyper head One head gasket REQUIRES: Installation to the engine with six 3x15mm screws (OSMG8743) SPECS: Height: .90" (23mm) Diameter: 2.13" (54mm) OS EnginesPart OSM25204200