Allegro's easy to order, easy to use Complete Ventilation Systems including all the most-asked-for equipment you need for your confined space site. The systems include a choice of Allegro's most popular blowers, six feet and fifteen feet of ducting with a storage bag, and a Manhole Ventilation Passthru (MVP). The Axial Blower Systems offer lightweight portability with the highest output available from axial-style blowers. See individual blower descriptions for CFM, weight and other specifications.