Providing maximum heating performance in a small 12-volt DC furnace. Easily installed in low height or basement areas that might otherwise just be unused space. Can be installed with only a flush mounted vent cap on the exterior wall or be installed with the optional exterior door for service access without entering the coach. Quiet burner operation, sealed forced-draft combustion, energy saving direct spark ignition, low amp draw and almost limitless design flexibility make this a real winner. DOOR NOT INCLUDED. Cut-out size: 7-1/2" H x 17" W x 20" D. 1 per box.