COMPATIBLE: Great replacement for the Blue Air 211,replacement HEPA Filter Compatible for Blue Pure 211+ and purifiers ;Use a 360-degree air intake, allowing the air filter replacement 211 to last , and has a collapsible design. BUT AFFORDABLE PRICE: We deliver high quality, durable and long-lasting replacements, allowing the filter to last , and has a collapsible design. In order to improve the performance of the air purifier, please replace the carbon filter every 6-8 months. EASY TO INSTALL: Simply remove the older and dirty filter and replace it. Please the filter with your unit is collapsible and slides into a metal cage to install. Colour:White Material:activated carbon Package Contents: 1 x 211 Filter Replacement Only the above package content, other products are not included. Note: Light reflection 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.