If your filter is worn, damaged or simply lost, you can now simply replace it and at a low cost. These filters are fully washable, however you may want to order more than one to keep a spareHigh quality after market part£2.99
Dyson Handheld Cordless Blue Cyclone Clip & Spring DC30 DC31 DC34 DC35 DC44
This will fit all models of the models listed below:
DC30 DC31 DC34 DC35 DC44 DC45 DC56 DC57
Although it does look similar to the one seen on the DC16 it will not fit this model.
These can be tight to get on but they do fit.
Dyson never made this part, so this is a high quality after-market new part