Review on Grey Industrial Style Helmet Car Aromatherapy Fragrance Diffuser with Silicone Clip - Includes DIY PE Block for Car, Home, and Office Use by Justin Sharp

I love this little air freshener helmet. The vent clip on the back keeps it on the vent well. When you open the bottom door, it reveals a small bowl that contains the oil for the diffuser. It has a small indentation where you drain the oil and then put it back in. It doesn't give off as much fragrance as an essential oil diffuser. and I can barely smell the smell that comes from it. But that's because it's hot outside now and the air conditioner is blowing cold air through them. I think in the summer when heat is coming in through the vents this will work better to release the flavor from the oils.