objective end only, alumina flips on leupolds or butler creeks for everything, mount them somewhat cockeyed so the tab lines up naturally with your thumb when you go to open it in a hurried hunting situation, easy to set up, just close your eyes and pretend you need to find it immediately because you forgot to open it and are trying to find the buck of your life in a black scope lol, some placements will have you ripping your thumbnail off especially with the leupold alumina's but they are such a nice flip, the butlers don't have that issue but you don't want to be reaching for the tab and missing it without looking first, you want thumb to hit it naturally
for lots of field use and weather like backpack overnight type hunting I like them, but for the more truck based day stuff I don't like them and generally keep them off until I'm packing in somewhere, I tend to carry rifle nose up either over shoulder or in kifaru gun bearer on pack, the eye piece end flip caps just slow you down and aren't really necessary to keep weather and debris of that small piece of glass that's usually hanging downward giving natural protection