2012 Toyota Prius Owners Manual - Page 607

3-1. Using the air conditioning system and defogger Micro dust and pollen filter button Operates micro dust and pollen filter on/off. Outside air mode switches to recirculated air mode. Pollen is removed from the air and the air flows to the upper part of the body. Usually the system will turn off automatically after approximately 3 minutes. 3 Interior features 285 PRIUS v_U (OM47674U)