Revolutionary bipod offers exceptional features at less cost. Weighs only 8oz. Simply press the "snap-n-lock" button to fold legs forward, down or rearward. To extend/retract legs in ONE SECOND from 9" to 13", twist thumbnut screw. All hardware is included for installation without gunsmithing. Will not scratch rust or dent. Allows use of a sling (sling adapter included) and includes non-slip rubber feet. Made in the USA by Advanced Technology, Inc of black, glass-filled nylon. Lifetime Warranty. M-4 requires hole drilled through handguard's aluminum double liner.