Airfan

The brand name points the wrong way, so first things first: Airfan supplies no fans here. The range is the Odor connect units at 125, 160, 200 and 250 mm, which you fit into your ducting, and the scent oil that goes with them. That oil comes as Dream, Easy, Happy, Love and Magic in 100 ml spray bottles, plus a 100 ml refill pack for the Odor connect itself.

The diameter, and spray against refill

All of it is under Climate and Ventilation, because the units go into the extraction run. Watch your duct diameter when picking a unit, and note that a spray bottle and the refill pack are two different items: the spray is used in the room, the refill goes into the unit.