[Filter Sticks Size]0.31(Diameter) x 2.75 (Length)inch. You can cut it to fit with your diffuser/humidifier if necessary.[Replacement]We advise our customer to replace the filter after 3-4 months use (depending on usage and water quality).[How to Use]To see a better performance, we advise user to soak a filter stick to be wet completely before inserting to the humidifier.[Advantages]Prolong the service life of diffuser: if the diffuser/humidifier is always complete-blocked or half-blocked, it will become hot and become broken easily, we highly recommend you to use water-solubility essential oil and clearwater.Usually 1 to 2 weeks, replace the filter, or easy to connect the machine. If you regularly use essential oils, need to replace 3 - 6 days.Size:7cm in length and 0.8cm in diameterMaterial:Cotton swabColour:whitePackage Contents:50 * Humidifier Sticks Cotton Filter Sticks(Excluding other display items)Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.