Wilson Combat's take on an adjustable rear sight

It is a nifty design but of course requires that you're getting a wad gun built from the ground up.  Still, it is a welcome feature to iron sight shooters who would benefit from being able to choose among different notch configurations for different conditions.  It doesn't look like you have to turn out a staked-in nut to disassemble as you do for a typical windage assembly.
https://shopwilsoncombat.com/Lo-Mount-Adjustable-Rear-Sight-Standard-Blade/productinfo/428W/

When you see the milling (below) required, you'll see another unique idea - an alternative to the traditional dovetail.

[url=http://www.wilsoncombat.com/press/428 Sight Cut.pdf]http://www.wilsoncombat.com/press/428%20Sight%20Cut.pdf[/url]