Alumina Flip-Back lens covers feature powerful neodymium magnets to hold them securely closed and triple O-ring seals for provide maximum protection from the elements. The cover opens silently and folds flat against the scope in the open position. *Compatible with Leupold post-2004 riflescopes with 33mm objective lenses as well as the VX-3 and VX-3i 1.75-6x32mm. Not compatible with VX-3 Handgun 2.5-8x32mm.