BUIS Fundamentals and recommendations

Examines the distinction between a folding rear sight and a back up iron sight and use case for each.

Rear sights shown:
KAC (Knights Armament) Folding Micro Rear Sight, 200-600 Meter Adjustable PN:25650

Knockoff Dueck Defense Rapid Transition Sights (RTS-1 , RTS-2)