Most likely this is not a hot tub, but an inground spa. A hot tub is portable. You can find a pool or spa builder in your area or a hot tub retailer nearby by visiting our member locator. Here's a great place to start if you're considering purchasing a hot tub here's a great site where you can find information on Buying a Hot Tub.
Techo-Bloc
The Association of Pool & Spa Professionals