The BSA Optics 42 mm Red Dot Sight (RD42, Clam Pack) is a flexible red dot sight for your rifle or shotgun, made for all types of shooting conditions. It is perfect for pistols and ideal for mounting on a shotgun when turkey hunting. When the gun sight is activated a small red dot appears in the center of the rifle scope. The reticle brightness can then be adjusted for the best results. Choose the push-button brightness control or the 11-position click rheostat. The light weight BSA Optics Huntsman rifle sight is light enough for small calibers plinking on the range, yet this BSA Optics scope is durable enough for larger calibers used by hunters and law enforcement departments.