The Caldwell Accumax Premium Carbon Fiber Swivel Stud Bipod fiber legs are super strong and lightweight and feature non-slip rubber feet. It securely attaches to any sling swivel stud. The twist-locks allow for fast incremental leg length adjustment. The legs lock forward or backward at 90 degrees with spring-loaded buttons. Secure leg-stops prevent legs from overextending. It is extendible from 13 inches - 30 inches.