We recommend replacing your DuoVac filter every few years for 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 Star
DuoVac Air 50
DuoVac Distinction
DuoVac Select Plus
DuoVac Symphonia
DuoVac Enforcer
DuoVac Colossus

Husky Pro 200 
Husky Storm