This is a Caldwell Bipod known as the Sitting, model 532255.
Caldwell's AR-15 Sitting Bipod 14.5"-30.5" Picatinny Mount is easily attachable and detachable to any Picatinny rail. It features 18 degrees of available cant (tilt) in either direction and rotates left or right 20 degrees" without repositioning bipod legs.
Features:
Fully adjustable with fold up legs
Tilts and pans
Lockable legs
