This bipod features a hinged base with tension adjustments to minimize tremors and prevent the recoil from loosening the bipod from the firearm. Simply attach to your sling swivel for steady base to hit your target. The rubber feet prevent movement. Series SSeven height settings from 9 to 13 inchesLegs eject by spring actionAluminum alloy with some steel partsHard lubber leg capsAttaches to sling swivel studHinged base has tension adjustment and buffer springs to eliminate tremor or looseness