I have worked with Del on and off for close to twenty years. They have always been very good to deal with. Years and years ago I was the closest dealer who would talk to them, so they sent some engineers to my store to talk with me, photograph the HotSpring tubs, and sketch out a system which could be added to the product. Watkins did not support the use of ozone at the time. They sent me a couple to install on my display and home tubs. Beta tested them and started selling them before they were mainstream.
They are the ones who make the ozone unit for HotSpring Portable Spas, and now you can buy a similar unit for your own tub.
8-)