Allegro Centrifugal Air Driven Blower System Allegroâ€TMs Complete Ventilation Systems include all the most-asked-for equipment for your confined space site. The systems include a choice of Allegroâ€TMs most popular blowers, six feet and fifteen feet of ducting with a storage bag, a Saddle Vent, a 90° Elbow, and a Universal Mount. The Centrifugal Blower Systems offer lightweight portability with the highest output available. See individual blower descriptions for CFM, weight and other specifications. Saddle Vent is a registered trademark of Air Systems International, Inc.; the Saddle Vent device is protected by U.S. Patent Nos. 4,794,956, 4,982,653, and foreign patents. ÂAllegro Industries