A conveniently moveable, mains electricity (AC-powered) device used to create and deliver ozone (O3) - also known as trioxygen. It typically produces a high electrical voltage between electrodes, to convert bottled oxygen (O2) into O3 when passed through the electrode gap. It usually includes measuring devices to determine output O3 concentration, and a mechanism to destroy internally the unused ozone; it is typically used at the site of application because it is not possible to store ozone. O3 has been used for various purposes in the laboratory, to disinfect/purify air and water, and in some clinical treatment of diseases.