The MBUS Pro (Magpul(R) Back-Up Sight) 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 and no-tool, elevation
adjustable Front excel in all 1913 Picatinny rail mounting applications,
including rail-height gas blocks. Positive detents keep the MBUS Pro
Front and 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.
Narrow width Front is compatible with most IR aiming laser and light
installations for the professional user.