Spring loaded foldable legs. Extendable legs feature posi-lock wheel and quick retraction button. Dual mounting can be use it with either Picatinny rail or swivel stud. Picatinny mount and swivel stud mount (included). Fits Picatinny/weaver style forends rails. Strong and lightweight aluminum construction. Rubberized feet for a more stabilized shooting position. 8''-11''.