Aprilaire model 6618 18" round motorized zone damper. Power close / spring open operation, 24 VAC, two wire. Items are new and unused in original box. Please call 952-884-8266 Mon thru Friday 7:00 to 5:00 or 612 518-6683 after 5:00 and on weekends. We ship nationwide. Minnesota residents will be charged sales tax.