Leupold Alumina Flip-Up Lens Cover 28mm

I bought this for my 2-7x28mm Rimfire scope, and I am very impressed (but completely unsurprised) by the quality of this cover.
It is constructed of aircraft aluminum that screws neatly into the integral threads at the objective end.
You simply screw it on until tight, being careful to keep the cover itself in the upright position when fully tightened, then you're done.
Just a slight bit of mechanical ability is all that's needed.
Once installed, they don't protrude much at all, and the construction is very rugged.
They even look elegant, with the familiar Leupold logo on the cover itself.