Proprietary composition of Cushinol℠at temples and nose pads create a non-slip fit that keeps sunglasses in place during athletic activity. Cam-Action Hinges℠allow the temples to quickly lock into position. Mastoid Temple Grip℠ensures the temple ends hug the mastoid bone (behind the ears) which allows for a secure and comfortable fit. Glare-reducing polarization treatment. Double Snap-Back Interchange Lens Systems allows you to quickly and efficiently switch between Native's different lens options. Anti-Ocular Intrusion System is designed to prevent the lenses from dangerously shooting toward the eyes in the event of high velocity impact. The Frisco Polarized is available with these color options:Gray Polarized Lens - 12% VLT (Visual Light Transmittance). Suitable for bright sunlight.Copper Polarized Lens - 18% VLT. Suitable for moderate to bright sunlight.Silver (Gray Base) Reflex Polarized Lens - 10% VLT. Suitable for extremely bright sunlight.Brown Polarized Lens - 12% VLT. Suitable for moderate to bright sunlight. Best fits a large profile. Case, one set of SportFlex℠lenses, and neck strap included.