We recommend replacing your DuoVac filter every few years for the best performance. It catches all the finer dirt and debris that the bag can't and prevents anything from entering the central vacs motor if the bag should ever tear.  

This filter fits the following models:

DuoVac Air 10 
DuoVac Select 
DuoVac Sensa 
DuoVac Solution
DuoVac Torpedo
DuoVac Design 650AW
DuoVac Design 655AW
DuoVac Premier Typhoon