Julbo Kid's Booba Sunglasses, Spectron 4 Baby Lens Spectron 4 lens is a dark lens, blocking 95% of the visible light, for max protection for your child's eyes Sipe Grip Tech- Supple, sculpted inserts at the stem ends for excellent hold without sticking to hair Flex System- Articulated hinges at temples for added comfort for various head shapes Curved temples- temples shaped and cut for better hold with sharp and repeated movements Like all Julbo lenses, these lenses are optical category 1, guaranteeing 100% protection against UVA, B and C rays