When you first get your beautiful auto diffuser take the eyedropper included and apply two or three drops directly into the top of the diffuser. When your ready your vent clip comes with three extra pads. To open your vent clip just undo the small split ring(small keyring) and open diffuser. Pads are washable. Change the pad to change scents or color that comes through the front design. Put the keyring back on and you are good to go