Leupold 176886 Integral Mounting System Mark IMS Black Aluminum 35mm Tube AR-15/M16 Picatinny Rail Mount
The Mark IMS family easily eliminates the two most common issues faced when mounting standard riflescopes to AR-style rifles; scope height and eye relief. This model is designed to fit AR's MIL-spec 1913/Picatinny rail and any scope with a 35mm maintube.