I have a 552. It runs off two AAs. I changed them only once during my deployment, and that was just because I was suspicious that they had lasted so long. It's NV compatible, and can take a magnifier mounted behind it. I mount it ont he flattop; some people prefer theirs mounted above the handguards.
Very solid piece of kit, very effective. No eye relief, no cheek weld, no parallax, open field opf view... Everything an unmagnified sight should hope to be.
The nation that makes a great distinction between its scholars and its warriors will have its thinking done by cowards and its fighting done by fools.