The interior finish on the Rubadub Tub® is made from PVDF, an easy-to-clean industrial tank lining material designed for high-temperature service. Its semi-gloss finish resists chemical and weather damage just like acrylic. Many people mistake PVDF for pool vinyl. Pool vinyl does not hold up to the high water temperature you have in hot tubs. BEWARE! Some manufacturers use vinyl liners in their hot tubs. The life expectancy of these liners is only 1–2 years. Our tub and liner carry a Ten Year Limited Warranty - the longest in the industry!