WantMall Adjustable Helmet Strap Mount Adapter for Sport Camera Gopro HD Hero 2 Hero 3 Durable nylon strap is easy to install and remove One size fits all Vented helmet mount for Gopro cameras, bike, kayak, surf, skate, snow, etc Compatible with GoPro Hero 2 / Hero 3 Adjustable design, the adjustable size of the strap is from 10cm to 30cm