A lens cap that stays firmly attached to a lens by screwing into the filter threads. As an added feature, the lens cap fits both 58mm and 53mm standard filter threads, perfect for a day of shooting and alternating between a couple of lenses, or just for the added convenience of two lens caps in one. I have been using a test print of this item for almost a year now in 58mm/67mm. All my problems disappeared when my lens caps stopped doing so. For design/testing notes on this and other 3D printables, visit thebilder.wordpress.com or follow @bilderstudios.
It's starting even to look like a triple lens cap!