ADVANTAGES OF REUSABLE FILTER SLOTS - Reusable and easy to replace. They make for your machine more cost-effective and can reduce plastic pollution to be friendly to environment. FOAM POLLEN & ULTRA FINE - The foam version is to block particulate matter. The ultra fine version is to block fine particles. Use to the cleanest air. FOR HEALTHIER LIFE - kit is designed so as to you and your loved ones with the cleanest air to maintain the health of your lungs and keep the potential diseases from you. Reusable Filter Slot Replace Once 3-6 months,Disposable Ultra-Fine Replace 2 weeks. Specifications: Applicable models: For DS500 / 700, etc Colour: blue+white Material: ABS+cotton Size: 6.8x6.8cm Package Contents: 6 x Reusable Filter Slot Replace 6 x Disposable Ultra Fine Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.