Wall mounted, and battery operated (takes 2 x AA batteries).
Simply place the ONA block into the slot inside the dispenser, and switch on the fan. This will drive ONA out of the dispenser and into the surrounding area.
Set to 24 hr, day or night operation. Continuous, 2/2 or 5/15 min on off running time.
Note: For best results, remove ONA Block from packaging before placing into dispenser.