Manufacturer: NcSTAR MARFLR
For a durable and compact flip-up rear A2 iron sight the NcSTAR MARFLR is the AR-15 back-up rear iron sight that you're looking for.
The MARFLR will fit virtually all AR-15, M4, and M16 flattop Picatinny rail upper receivers.
Specifications and Features:
A2 rear sight assembly with large and small rear aperture
A2 rear sight is fully adjustable for windage with knurled click adjustable controls
Large steel thumb nut and precise rail clamp for positive and secure attachment to your upper receiver
Folded down: 1.8” Length x 11/16” Height (mount height) and 1.1” Height (A2 sight base when folded)