The 265g O2 is a relatively straightforward lid that has been around for close to a decade. It has 24 vents and comes in three sizes (Small covers 52-56cm, L-XL ranges from 55-61cm and XL fits 61-64cm heads. While the XL is only available in matt black, you can get the smaller sizes in matt black, matt orange, matt white and this matt black and blue.
We’re fans, too, of the Rollsys adjustment system that works around the whole circumference of your head. Yet it’s the range of add-ons that really brings interest and allows you to tailor the 02 to your riding needs. Optional extras mean you can buy a net to stop insects getting in, an Aeroshell to reduce drag (or prevent rain ingress). If it’s cold there is an optional cap and there’s even a Cappuccino lock to use the straps as an anti-theft device for your bike.