Compatibility: The pre-motor filter is suitable for Dyson Big Ball CY22 CY23 CY24 CY25 CY26 CY27 CY28 DY75 DY77 DY78 vacuum cleaner. Washable and reusable: Wash in warm water and allow to dry completely before reusing. A mild detergent can be used if necessary. To ensure your vacuum cleaner works properly and optimally, it is recommended to replace the filter every 4 to 6 months. Premium vacuum cleaner filters feature a 2-in-1 design with high efficiency in blocking fine particles. Floating dust, etc. The filter is made of high-efficiency filter material, which can effectively filter dust to prevent large dust particles from entering the motor and ensure a long service life of the vacuum cleaner. Contents: 2 x pre-motor filters, replacement number 967371-01. Note: The data is all measured manually, please allow 1-3 cm error, due to differences in light and display There may be color difference, please refer to the actual item received.