The PFV models are mounted outside the tank (cistern). A vent pipe enters the rear of the toilet tank, above the water line, and the Panfan (6Vdc) is mounted within the pipe line extracting odours directly from the bowl creating a vacuum within the air cavity of the tank, using the internal overflow pipe as the air passage way from the bowl and exhausted outside.

The PFV model are only available in mains power supply, and come either as manual switching or touch free auto sensing.