Nobody wants to wonder if they have unwanted visitors living inside their spa. Our unique unibody design makes this virtually impossible. Peace of mind is built right in. An amazing amount of portable spas require very expensive repairs resulting from these pesky visitors. Our unique polymer GRANITT TM shell surface that is extremely durable and easy to clean. Simply wipe it down as needed. The GRANITTTM shell is resistant to exposure to the sun, has a high temperature resistance and is SUPER IMPACT RESISTANT!!!! Virtually impervious to the weather.