AC Com-Pax-ial Blowers are designed with tough steel construction , durable rubber feet, durable grill and carry handles. Extremely lightweight and powerful, these units include a venturi inlet to increase cfm. AC electric motor. Blowers are sold separately or with quick connect 15' or 25' ducting canister. Free air; 778 or 645 with one 90° bend, 496 with two 90° bends.