Environmental Material: The filter elements paper is made of environmental materials, and the whole is made of high-density fireproof fiber filter paper. It is non- and has no irritating odor. It filters impurities in oxygen to oxygen quality Oxygen Concentrator Accessories: Our filter is the perfect filter accessory for the oxygen concentrator, which can effectively extend the service life of the oxygen concentrator Easy To Carry: Small and light, more convenient to carry, suitable for workers who replace accessories outdoors Wide Range Of Adaptation: Suitable for 90% of the oxygen generator equipment on the market, easy to use How To Use: Open the back cover, remove the old filter, insert the new filter, and then close the back cover Colour:As Shown Material:plastic Package Contents: 2X Oxygen Generator Machine Replacement Filter 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.