This kit includes several different intensifiers for various conditions, each helping to enhance the visibility of game animals and targets. Included in the kit are the Alumina Intensifier BZ (bronze), the Intensifier OG (orange), the Optimizer, and the IS-Stacker (protective cover). The IS-Stacker provides a compact, durable storage device for the Alumina Intensifier Kit components. Thread your intensifiers and optimizer together with the IS-Stacker front and rear covers to form a durable, protective capsule that can be tossed into a pack or pocket and retrieved as needed. The component of the stacker marked with the circle-”L” Leupold medallion can double as a protective lens cover for your riflescope as well.