This seat back rifle rack includes Grey Man Tactical(TM)& leading rifle rack updated to include the anodized black buttstock cup and 6extension to allow the buttstock of the weapon to drop down near the floor board. It also includes the popular Master Lock(TM) Python cable lock to pass through your weapon when needed for security, making this a great choicefor your safe weapon transportation needs. Package Contents: QTY 1 -15.25 X 25 RMP(TM) QTY 1 -Buckle Loop-Around + D-Ring RMP Strap(TM) Black [Headrest] QTY 1 -Buckle Loop-Around RMP Strap(TM) Black [Seat Bottom] QTY 1 -QuickFistGo-Between Clamp - Enlarged [Handguard] + RMP Backer Plates QTY 1 - RMP(TM) Buttstock Cup Kit - Standard OR XL Cup - Black Anodized QTY 1 - RMP(TM) Buttstock - 6Extension - Black Anodized QTY 1 - Master Lock5/16Python Adjustable Locking Cable Compatibility: This seat back RMP(TM) is compatible with all vehicles from compact cars to full sized trucks, helicopters to MRAPs. The 1nylon webbing and heavy duty buckles loop around the headrest and around the seat bottom and cinch to a snug, solid fit. Included D-Ring& can be used instead of the loop around strap by lifting adjustable headrests out of their socket and slipping the D-ring onto the headrest post. Buttstock Cup Compatibility: XL - Aftermarket stocks that are wider or taller, along with most pistol braces will fit into the XL.Internal Dimensions: 6.25long x 2.6wide tapered down to 1.72wide x 1.29deep. Specifications: WIDTH15.25"|387.35mm HEIGHT25"|635mm THICKNESS0.188"|4.77mm WEIGHT85.63 ounces|2427.56 grams MATERIALInjection Molded Glass Filled Nylon