Built with the brilliance of integrated cam-action barrel hinges, the Tinfoil is what happens when industrial design DNA wraps around stainless steel & reinvents the idea of wire frames. Hollow, screwless cam hinge allows product longevity & there is an intricate hinge barrel design. Durability & all-day comfort of lightweight, stainless steel frame material, with non-slip Unobtanium earsocks & air-filled silicon nosepads for secure, snug fit. Lenses with this frame: Black Iridium Polarised: Extremely bright light. Excellent all-purpose lens for sunny conditions. Offers truer colour perception. Features an Iridium coating to reduce glare.