O3 is ozone. It attaches an additional oxygen atom that is less stable to the 02 (normal air we breath) molecule. This unstable atom wants to jump to another molecule as soon as possible (the air or surface of the sauna). When it does this, it changes the make-up of that molecule it jumped to. By changing the molecule of odor, mold, etc., it disinfect.

• New Oxygen Ionizer used in any Infrared Saunas
• It disinfects the sauna, it ionizes the air while you are in the sauna.
• It has a 15 minute timer. You turn on O3 when you turn on your sauna go warm up. It automatically switches to ionization after 15 minutes (which is fine to breath).
• It hooks up to your DC12V connection cord in your sauna. Mounts to wall.
• Includes: 1 Oxygen Ionizer, 1 Connection Cord, 1 Fragrance Pad
• AC/DC adapter NOT included