Charles Owen Adult Pro II Plus Skull Hat Silver. The Charles Adult Pro II Plus Skull has all the features of the Pro II with the added benefit of a removable headband which is washable and therefore more hygienic. It is the most breathable triple standard cross country helmet. The Pro II Plus is a low profile hat which helps keep your head safe and cool. The Charles Owen Pro II Plus hat features ventilated slots to the front and back of the helmet allowing air to flow, while interwoven silver ions provide anti-microbial protection against sweat and odours.