Blend air roof mounting plate for all Coleman Deluxe Blend Air units. Plate measures 15.5” x 15.5” with 9-3/4” ring for mounting crown. Mounts onto roof, box sticks inside attic. Box measures 8.5” x 5” x 5” deep. Round opening for connecting insulated duct. Open ends for exchange of attic air. Attic fan mounts in middle of plate.