SIZE WEIGHT HP CFM # OF DROP TUBES 15' 585 11.9 4000 CFM Max 14 16' 605 11.05 4000 CFM Max 13 18' 625 13.6 4000 CFM Max 16 20' 645 16.15 4000 CFM Max 19 22' 685 17 4000 CFM Max 20 25' 1475 21.25 4000 CFM Max 25 30' 705 24.65 4000 CFM Max 29