For serious pursuits, the Bloc Forty X860 Sunglasses are the perfect accessory. Constructed from XTR Karbon8 optical class 1 lenses, the X860\'s are hugely impact resistant. Not only hardwearing, the X860\'s protect against UVA, UVB and blue light.XTR Karbon8 optical class 1 grey lens with silver flash category 3Tinted on grey base - for bright light conditionsCAT 3 18-8% light transmission TR90 material - for strength and durabilityProtection against UVA, UVB and blue light up to 400nmTested to BS EN ISO 12312-1:201