I put this box in my 2015 GMC Sierra 3500HD Crew Cab and it is truly a match made in heaven. It fits perfectly under the back seat just as advertised. I didn't have to raise the seat at all. In fact, the seat is able to fold back down into it's normal fully down and locked position. And the performance is incredible! Even though this box is designed for 6.5" subs, it is capable of hitting a wide range of frequencies. The design and look of this box is second to none. Great fit and finish and it looks amazing in my truck!