Quest Return Air Duct Collar for Dual 105, 155, 165, 205, 225, 185 Cool Overhead DehumidifiersThis accessory allows a limited amount of ductwork to be attached to the intake on Quest Dual dehumidifiers. This allows the dehumidifier to be located outside of the indoor garden. Be sure to also purchase the supply air attachment (part #310784) to attach ductwork to the air outlet and send dry air back into the garden. This 12 inch flange fits the Dual 105, Dual 155, Dual 165, Dual 205, Dual 225 and 185 Cool only.