imported metal frame non polarized bridge: 13 millimeters arm: 139 millimeters patented high definition optics (hdo): oakley's high definition optics provide superior optical clarity and razor-sharp vision at every angle as well as clarity and protection against impact and uv light, filtering 100% of uva, uvb, uvc, and harmful blue light up to 400mm. oakley clear lenses: these clear lenses allow 89% of light to come through, making them perfect for use in low light to no light conditions. o-matter stress resistant technology: o-matter oakley frames are lightweight and durable for all-day comfort and protection. they're injected with molded thermoplastic o-matter frame that provides improved strength and flexibility, and is designed to withstand shifting or deforming over time. youth fit: the oakley knuckler eyeglasses are scaled down to fit kids or people with smaller faces.