I bought one for an objective lens and thought the same thing Coulee did, that I couldn't screw it on to the scope without taking the scope out of the rings, but I was wrong. The inside bezel of the scope cover moves independently from the cover itself, so you can attach or detach it from the scope without having to remove the scope. It figures Leupold would be smart enough to make them that way. I haven't had occasion to use the scope cover in the field, so I can't really comment on its utility, but I've lost my share of Butler Creek scope covers in the past, and the screw-in attachment is definitely more secure. I picked mine up for a discount in the Bargain Barn at Cabelas. I suspect they get a few returned because of the apparent clearance problem.