Timberwolf Economizer EPA Wood Burning Fireplace Insert Minimum fireplace opening: 25-7/8" (W) x 22" (H) x 14" (D) Flashing dimensions: 43-5/8" (W) x 31-3/8" (H) Heats up to 2,000 sq. ft. Includes 2-55 CFM blowers 6" flue diameter, Top Vent