These small diffusers are perfect for hanging in your car but can also be used in other small spaces. 8 ml of long-lasting fragrance. To Use: Twist off the wooden cap and remove the plastic plug**. Carefully replace the wooden cap, tightly, gently shake the diffuser to wet the wooden cap. The fragrance is diffused through the cap and the hanging string. **I recommend saving the plastic plug in case you want to try another scent. Put the plug back in and you can save your partially used diffuser! Notes: Shaking too much can soak your string and cause drips, so be gentle :) The strings are held with a small wooden ball, only by tension. If you find that your diffuser is shaking loose, you may need to tie your string to keep it secure. Check that your cap is tight, every once in a while. These are soft wood and they can shake loose over time. I make my diffusers 25% fragrance oil for full immersion and longevity. They are on the stronger side, but not overwhelming. If you find the scent to be too much, move the diffuser to the back of your car or replace the plastic plug and let the wooden cap dry out a bit.