Bobster Spektrax Sunglasses (MATTE BLACK) The Spektrax is ideal for riders requiring prescription lenses, this eyewear converts smoothly from sunglass to goggle with the included detachable strap. The removable RX insert fits securely between the shatter-resistant polycarbonate lens and the anti-impact frame which is lined with open cell foam. Excellent peripheral vision is produced from the curved, single-lens geometry. Temple to temple: 147 mm. Polycarbonate anti-impact frame.