BDC 250 Muzzle Loader IR was designed to deliver a high level of confidence at extended targets that can be used with today&';s most popular muzzle loader rounds. FULLY MULTI-COATED Effectively reduces reflected light and increases the transmission of light giving you a brighter image than normal single coated lenses WATERPROOF 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. NITROGEN PURGED Nitrogen gas is used to purge air from the optic to help maintain internal fog-proof and waterproof capabilities.