Magpul MBUS PRO Rear Sight (MAG276)

Magpul

The MBUS PRO is a corrosion resistant all-steel back-up sighting solution that delivers maximum functionality and strength with minimum bulk at a price that's even smaller than its size. The dual aperture, windage adjustable rear sight is contoured to fit seamlessly on the tail end of AR15/M4 receiver 1913 Picatinny rails to avoid charging handle interference.  

Positive detents keep the MBUS PRO rear at standard AR sight height when deployed, and so low when they are stowed that you'll never notice them until they're needed.

$ 104.95