In addition to hydration, moistening your mouth is said to be effective for infection control. It seems useful for gargling while out and about. The capacity is about 120ml, so it's light (the main unit weighs 120 grams) and small, so it won't take up much space in your bag. You can also repeat the process of "refilling when empty" when you're out, which I think is good for hygiene. It is an unused item, but it has been removed from the box and stored on a shelf. It is not a new item, so please refrain from purchasing if you are concerned. Bulk purchases are welcome. I am also selling various other items, so please take a look at my other pages. I will offer a discount for bulk purchases. Please leave a comment or use the bulk purchase request function. Thank you for looking.