Dometic Return Air Grill For FreshJet Ducted Polar White (3318090.000)Set up clean, thermostat controlled cooling in your ducted RV with the Dometic FreshJet Return Air Grille with Quick Cool (Part #3318090. 000) in polar white. This return air grille is designed for ducted applications, allowing you to use a wall thermostat with FreshJet air conditioners that have pre installed electronic controls or that have been upgraded with electronic controls. Wall Thermostat Control for Ducted Systems By routing return air