We believe this system to be the the most stable shooting platform on the market. System Includes: TSP Gun-Jaw with 6-Pad System 1913 Picatinny rail, With 2 Rapid Close/Open Butterfly Knobs. Specification: Ball: 2.75-Inch 6061 Aluminum, Type II, Class III Hard Coat Anodized With A Special Aerospace Teflon Coating. Special Delrin Sleeve Body: Solid Billet 6061 Aluminum, Type II, Class III Hard Coat Anodized. Base: 360 Degrees Panoramic, Solid Bar Alloy Steel With Black Oxide finish With Locking Knob. Standard Size Tripod 3/8-16 Thread Control Handle: 3-Inches Long, 1.5-Inch Diameter. Controls Tension / Movement Of Ball.