Our neutral simple Car Diffusers come pre-filled with 8mL of our fragrance oil blends! These car diffusers leave your car smelling wonderful for a month or more! With our car diffusers, you are able to control the intensity of your scent! If you want your scent to be strong, turn your diffuser upside down for 4-6 seconds. If you want it to be soft, turn the bottle upside down for 2-3 seconds. Depending on how intense you want it to be, will determine how long it will last you.