Product Reviews for MARFLR - NcStar AR15 M16 M4 Flip Up Rear Sight AR-15 M1-6 M4 Flip Up Rear Sight by Chad Andeson (2025-12-07 16:13:03) Rating: 5 / 5 - 5 - Excellent Owned Product for: more than 1 year Pros: This AR-15 M1-6 M4 Flip Up Rear Sight is a good upgrade from my old one. Im very happy with it. Cons: Other thoughts: