The Grander Polarised Sunglasses with CRYSTALIT Technology are purpose built for extreme marine environments, offering maximum glare protection and visible clarity. Rated CAT:3 VLT (Visable light transmission), these Polarised Suglasses have been specifically designed to maximise your experience when out chasing big game on the ocean, where there are overwhelming shades of blue on the open water. Blue light filtering to enhance your vision, block glare and increase comfort to the eyes.