These are nothing fancy but - Lion Gears 45 Degree Angle Mounts

These may not be a fancy tricked out heavy duty mount, but they fit my PSA AR hand guard upper picatinny rail very well. My factory Magpul flip up sights mount and lock on with out a problem. The only thing some may not like is that the backup sights sit a little high off the hand guard. From my measurement, the bottom of the pic mount area ( where the backup sight mounts ) is about 3/4 inch from the actual hand guard. But it clears my scopes add on throw lever and the shell deflector. Hope the measurement helps someone. P.S. Do NOT over tighten the mount screw / bolt and remember to use medium strength Loc Tite #242 on them and your flip up sight mount screws.