Size is L, approximately 59-60cm. It's a model from a few years ago, but it hasn't been used much and has been stored. I'm selling it due to moving. The helmet bag says "Aircraft Carbon," but please note that it is not a carbon model. Would be suitable for downhill, etc. - Brand: 100% - Color: Orange/Black/Silver - Model Name: AIRCRAFT - Type: MTB Helmet - Design Features: Glossy finish Thank you for looking.