Nylon Frames: - Hydralon - Bolle's proprietary nylon frame material is virtually indestructible and comfortably lightweight. Thermo-Grip - Super strength rubber temple tips and nose pads deliver firm, comfortable adhesion, especially when you sweat. - Air Management -Unique venting designs integrated into many of our nylon frames create a potent anti-fog system. - Absorber Hinges - Like spring hinges, these ergonomically designed hinges provide appropriate tension on the temple for a comfortable, snug fit. - Wire core Temple Tips (Vigilante/Parole only) - Adjustable wire core temple tips allow increased comfort and a unique fit for each wearer. - Sport Optical System (SOS) - Bolle patent Rx adapter design allows easy attachment of prescription lenses to most of our interchangeable lens frames.