Caldwell Prone Bipod, Attaches to Picatinny Rail, Aluminum, Fits AR Rifles, Desert Tan 534455 Caldwell's AR Bipod Prone 7.5"-10" combines a quick attach system for securing to any Picatinny rail. Its built in systems for both pivot and cant movements give the shooter maximum range of alignment without having to reposition the bipod. The unique internal spring system is both low profile and quiet. The unique leg adjustment mechanism delivers fast and secure no-wobble height positioning. Rubber feet ensure good grip on all surfaces. Lightweight and durable anodized aluminum construction.