If you are looking to do ANYTHING CAMS related, the helmet needs to meet or exceed one or more of the following standards, AS1698 (Aus std), Snell SA95, SA2000, SA2005 (USA std), SFI spec 31.1, 31.2, 31.1A, 31.2A (USA std), BS 6658-85 Type A & A/FR incl ammendments (British std) or 8860-2004 (FIA std) (All these out of the 2008 CAMS manual) In my opinion find one that is obviously comfy and tight, movement is a major pi$$off, and also one that is light. The lighter the better. Can help you to focus more on the driving instead of having to fight the weight of the helmet on your neck.