Prefilter compatible with for A10 a11 hero A10 a11 master cordless vacuum cleaner Prefilter is very important for suction and suction efficiency You need to deeply clean or replace the filter regularly to prevent suction loss The pre filter can be flushed Please flush it with cold water and reinstall it after it is completely dry Replace the filter every 2 to 3 months Depending on the frequency of use, it can be replaced for a shorter or longer time The filter keeps the robot clean and reduces the penetration of dust, pollen and other allergens into the air you breathe Colour:Photo ColorMaterial:ABSPackage Contents:2 x filters1 x cleaning brush1 x English manualOnly the above package content, other products are not included Note: Light shooting 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 Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.