This non insulated stainless boot covers the insert opening and adapts to the flexible liner. Outside base is 10 1/8" wide x 15 3/8" long x 5 3/8" high. Inner dimensions are 9 1/8" wide x 14 3/4" long. Attach by drilling and bolting, or tapping and screwing into the insert top. Then seal the boots base to the insert with furnace cement.
Note: Flex liner does not connect directly to this boot. You must install an appliance/stove connector to the liner. The appliance/stove connector then connects to the Insert Boot.