Athlon Optics fully multi-coated glass gives you better light transmission with optimum brightness and true color across the entire light spectrum.High Density BAK-4 prisms produce a sharp, round exit pupil ultimately delivering higher light transmission and clarity to the edge of the image.Regardless of how heavy the rain is coming down or an accidental drop in the water, this sealed and gas-purged optic will remain waterproof.WARNING: Cancer and Reproductive Harm -www.P65Warnings.ca.gov