Description: Non-slip design Made of Nylon and polycarbonate Durable and Anti-slide Firm and reliable and Comfortable to wear Elastic adjustable strap to adapt to different head size Compatible with GoPro HERO3\HERO4\HD, etc suitable for outdoor sports like Surfing, skiing, kayaking, mountain biking Specifications: Material: Nylon and polycarbonate Color: black Compatible with: GoPro HERO3\HERO4\HD, etc Size: one size Fit for: all people Specifications: Non-slip design Made of Nylon and polycarbonate Durable and Anti-slide Firm and reliable Elastic adjustable strap to adapt to different head size Comfortable to wear Package Included: 1 * Head Strap Notes: Due to the difference between different monitors, the pictures may not reflect the actual color of the item. Compare the detail sizes with yours, please allow 1-3cm error, due to manual measurement. Please leaving a message before you give the bad feedback, if the products have some problems. Thanks for your understandings.