The Unibond Aero 360 Optimum Moisture Absorbing System helps prevent condensation, damp and bad smells, as well as the development of mould and dust mites, which could cause allergies. Ideal for every room inside the home and caravans/boats. No noise and no electricity.Refills available in neutral and 2 aromatherapy scent options. They last for approximately 3 months in a 20m² room.Unibond Aero 360 Moisture Absorber Refills last for approximately 3 months in a 20m² room. 2 x 450g Refill Tabs.