From the RAZR Series NEOX Technology: Neox lenses offer the sharpest and most accurate vision you can get for your game, enabling you to see angles and lines with greater sharpness. Tech / Performance style frame. Magnesium / Aluminum alloy construction. Lightweight yet highly durable material. Semi-rimless design equals zero distraction. Fits Med-Large head shape. Adjustable nose piece. Megol rubber nose and ear tips provide secure 'non-slip' retention. Ergonomically wrapped temple. NX14 lenses are slightly darker, allowing 14% light transmission.