The world famous golden VHM head with exchangeable combustion chamber is specially developed for optimal power output during the whole race and has an improved water duct. It's manufactured from a high quality alloy and O-rings are used for the sealing.
Use VHM standard insert:
AE32281-E (for OEM piston)
AE32281-013 (for 12° VHM piston APKT08521707)