Versatile, low profile furnaces offer maximum ducted heating for mid-size and large RVs. Designed for exterior serviceability with a rear (outside) gas connection. Exterior access door is required, The SF is aesthetically appealing and a more economical installation choice. Features identical cabinet dimensions for installation flexibility, quiet, multi-ported stainless steel burners, sealed forced-draft combustion, automatic direct spark ignition, and low amp draw. Cut-out size: 7-1/2" H x 17" W x 20" D. 1 per box.