Originally Posted by oldno7
Much better design than BC.
I don't see any difference between them & Butler Creeks.
But look at the stamp on an Alumina, and consider that these are not plastic copies of someone else's product:
Alumina® flip-back lens covers feature powerful neodymium magnets to hold them securely closed and triple O-ring seals for maximum protection from the elements. Their machined-aluminum precision construction, quick and easy operation, and a low-profile position when open make our flip-back lens covers stand above the rest. The round objective models are clockable, so you can rotate them to open any direction. Available in a variety of sizes for both eyepieces and objectives.