The GSR Pro-Strap is a quantum leap in strap design and security. The GSR gear lock system gives you precise tension control for a secure, comfortable fit. The extra wide head pad grips the back of your head, and distributes the force over a large area, ensuring ultimate grip and maximum comfort. Simply turn the dial and ratchet down your i5 to a precision fit. The GSR is a revolutionary step in goggle strap technology providing the ultimate in comfort and performance.