Combustion Air Kit Constructed from 12 gauge steel. Black powder coat finish. Model No. Size Box Qty. Width Height Depth 1084 4 2 8 10 1085 4 4 8 9 Combine with extensions when added length is needed Model No. Size Box Qty. Width Height Depth 1084EXT 4 2 8 10 1085EXT 4 4 8 9