The lenscoat pentax d fa 150 450mm f45 56 dc aw telephoto lens cover offers your valuable equipment some protection from scrapes and bumps preserving its resale value it also helps break up the shape of your lens making it less noticeable to wildlife it features a clear plastic window over the auto focus controls and comes with an optional piece for when the lens is zoomed out to 450mm which can be quickly and easily put on and removed with its velcro attachment