The PSR (Precision) Atlas BT47 Bipods came about as the Atlas was selected for the USSOCOM system. These changes include a non-rotational legs, fore and aft pivot limiting bosses and a 40% stronger Inner leg.SPECS:Height Range: 7–13".Preloaded Pan: 30 degrees.Preloaded Cant: 30 degrees.Position Button 0.5" diameter.Fore and Aft pivot limiting Bosses.5 leg positions: 0, 45, 90, 135 & 180 degrees.Non-Rotating Legs: outer leg does not rotate around inner leg.Larger, stronger inner legs.Weight: 15.13 ounces approx. (BT47-LW17) and 12.86 ounces approx. (BT47-NC) .Footprint: 10-14.5".MORE INFORMATION:UHMW components used for smooth tracking.Preload on Pan and Cant can be tightened by means of the knurled knob.Picatinny Rail Mount interface by either standard machine screw fastener based clamp or optional 17S lever mount.Solid leg positions allows shooter to load the bipod at the 45 and 90 degree positions. Non-orientated leg length adjustment done by either hand: Outer leg slides on the Inner leg locating on any of five positions 3/4" apart.Optional 3" Leg Extensions to increase height.