30 Green Rattan Reed Diffuser Sticks Replacement 30 Green Reed Diffusers 10" length, 3mm diameter Cut on ultra sharp blades which allows scent to flow easily 3mm diameter allows maximum wicking of scent Place as many Diffuser Reeds in a jar of reed diffuser oil as you'd like. We find that 3-5 works just fine, but many people add more (8,10,12+). Know that the more reeds you use, the more fragrance is released, and the quicker the liquid is used up.