Dimension One Spas® is committed to maintaining the quality of your tub. That’s why our patented UltraLast™ Covers have superior durability. They are UV, water, mold and mildew resistant to protect your tub against environmental exposure. Our precision engineering is evident in every detail of the UltraLast™ Covers design, both refined and reliable. Discover why an UltraLast™ Cover is the right choice for your spa, it’s built to last.