Every DU-HA is custom-designed to fit a particular model of truck. 19-21 Chevrolet/GMC Silverado/Sierra Light Duty Double Cab & 20-21 Heavy Duty Double Cab model is designed to fit underneath your pre-existing back seats. It's constructed from heavy-duty polyethylene and comes with a lifetime warranty. If your truck came equipped with a metal tray or a lid system under the back seat, you will need to remove the factory trays prior to installing your DU-HA. These trays are interchangeable, so you will be able to re-install them later if needed. This DU-HA holds 2 rifles or shotguns, with one scope, but may not act as a legal gun case in states with gun case laws, unless guns are first placed in sleeves. Check with your local authorities for the gun case laws in your state.