QCA spa shells are built for beauty, strength, and durability with our 4 layer Dura-Bond construction. All of our spas are backed by our comprehensive warranty and pass a 50 point inspection to ensure they will perform flawlessly in your home. Our spas are Underwriters laboratory (UL) listed, for your piece of mind, knowing that your spa has been tested to the rigid safety standards of UL / CUL. The GT500 is built to last with our patented Dura-Bond™ four layer strengthening process. The best components are used to build the GT-500 hydrotherapy spa. For ease and comfort of use, this hot tub features a Balboa electronic topside control for ultimate reliability. At the touch of your fingertips, use your Soft Touch™ control for your pumps, temperature up and down, time, mode, and light.