Dimension One Spas (D1) is the leading manufacturer of award-winning hot tubs and swim spas and home to the world's first curvilinear spa. D1 Spas is based in Carlsbad, CA and sold through a network of dealers in the United States and worldwide. With more than 35 years of experience, the company's product lines and patented features offer a unique class of design, performance and value for a stunning finish to backyards and patios around the world.