It seems that magnified and red dot optics are standard issue on rifles these days. Everybody has one, and lots of shooters have two! Optics are great and getting better all the time, but every marksman should know how to fall back on the standard iron sights.
Luckily, with ample rail space on most rifles today, you don’t have to make a choice between one or the other. The Magpul MBUS Rear Sight fits neatly onto your rail behind your optic and folds down out of the way to avoid interference. It has multiple apertures for aiming at different distances and is fully adjustable for windage.
With all the money we spend on AR-15 attachments, there’s no good reason not to have a good set of backup iron sights. You depend on your rifle to get the job done, and if your optic fails, you need to have a back-up at the ready. The Magpul MBUS is everything that you could ask for in this situation; lightweight, convenient, easy to use, and well-made to resist shock and other impacts. Great improvement to your rifle and a low cost for peace of mind.