The AR-15 Flip-Up MBUS Gen 2 Front Sight by Magpul is a low-profile, polymer backup sight that mounts on a flattop and deploys instantly with a finger touch.
It features a spring-loaded ambidextrous release mechanism, requires less than 1" of Picatinny rail space, and provides standard A2 iron sight height over bore.
The front sight is compatible with railed forends on the same plane as the receiver and is not suitable for railed gas blocks or MOE handguards.