Zeadio ZBP-013 13" - 22" Swivel Pivot Adjustable Spring Loaded Rifle Bipod [1 Year Warranty] Easy sling attachment. Designed for swivel stud mount. Fully adjustable legs with Posi-lock wheel and quick retraction button Extendable Legs: Length of both legs can be adjusted for best position. High-tech durable aluminum construction and steel top platform Includes limited 1 year manufacturer Zeadio's warranty