Yankee Hill Machine Q.D.S. Same Plane Rear Sight, Dual Peep YHM-5010
YHM's Quick Deploy Sight System features an automatic deploy system that springs the sight up with the push of a button. The rear sights lock positively in the folded and deployed positions and are made from aircraft quality aluminum and hardcoated to military specifications.
This YHM rear sight is dual peep aperture (YHM-5010). When folded the sight measures just .435 inches from the rail.