Duogreen is a registered trademark of iOttie, and it strive to provide the customers with the top quality products at all times. Duogreen undergoes series of rigorous screening processes of all its products through continuous testing and sampling to maintain its top notch manufacturing process. Duogreen’s current products ranges from DLP lamps, Irobot accessories and many more.Duogreen's replacement filter for Irobot Roomba 550 series/Aerovac 20938 are durable and longer lasting, reduces the amount of dust, pollen and other allergen infiltration. For the best result, please replace the filter every 2-3 months. Sometimes"Less is More!!"