High output with lots of flexibility. 40,000 BTU's of heat is ducted to 3 or 4 separate areas of the boat, keeping everyone warm and toasty. Amperage: Low 3.5, High 8.0Air Flow: Low 230 cfm, High 263 cfm Includes: Heater unit w/45° wrapper, 3" x 18' vent hose, 3-directional Euro vents, univ. mtg. brackets, wire ties, switch plate w/rocker switch and & High/Low indicator.