The Pro Chassis Bag Rider extends the surface area on the underside of the buttstock and allows for better contact with a rear bag. This results in a stable shooting platform, allowing the shooter to move forward and backward freely without moving the bag. Manufactured from 6061-T6 aluminum with Type III hard coat anodized finish. Easily Installs to the DELTA 5 PRO bolt-action rifle or Pro Chassis System in moments with provided cap screws and Allen wrench. Daniel Defense Delta 5 Pro Chassis Bag Rider 21-163-17085