Simple and convenient: The cartridge filter allows you to vacuum without any need for additional filter changes. The filter can be easily attached and removed by twisting it. No additional locking elements are required. In addition, the filter ensures excellent dust retention. Suitable for the Kärcher wet and dry vacuum cleaners WD 1 Compact Battery, WD 2, WD 2 Plus, WD 3, WD 3 Battery, KWD 1–KWD 3 and the Kärcher spray extraction cleaners SE 4001 and SE 4002.