This product is a high tech sun shade for rifle scopes which uses a honeycomb cell technology used by Army, Marine, and Special Forces to cut the glare that interferes with clear sighting. These ARD'S fit inside the Butler Creek Flip Open(TM) objective lens covers we stock for most scopes. The honeycomb cells are all but invisible through the scope, and they also prevent reflections from the scope lens from spooking game animals. ARD's come in six sizes, and must be used in conjunction with the appropriate Butler Creek Cover for your scope. Mfg: Tenebraex Corp