Designed to work with the Leupold 12-40X60 Spotting scope (M151) and the Badger Ordnance SLICK spotting scope mount (P/N 306-94). Provides rugged protection to the objective lens as well as allowing reduced light transmission and reducing glare via the variable aperture “Catseye” feature. Cover indexes out of the way for full light transmission. Made from 6061 Aluminium, Type lll Milspec Hard coat anodised Tan. 87 grams.