Maglite D Cell Accessory Kit Includes: Colored Lens Set The red lens is used to help maintain "night vision." General applications include: aircraft, boats, ships, military operations, police and security work. The blue lens helps penetrate through smoke and fog. Mounting Brackets (Fit D-Cell Only) Mount your Mag-Lite® flashlight on a wall, in a vehicle, boat, airplane or home. Lens Holder / Anti-Roll Device This item both retains a colored lens and helps prevent the flashlight from rolling off irregular surfaces. Note: The Lens Holder and Lenses may also be used on "C" cell Mag-Lite® flashlights.