SIZE WEIGHT HP CFM # OF DROP TUBES 15' 885 14.45 4000 CFM Max 17 16' 944 15.3 4000 CFM Max 18 17.5' 1033 14.45 4000 CFM Max 19 18' 1062 15.3 4000 CFM Max 20 20' 1180 19.55 4000 CFM Max 23 22' 1298 21.25 4000 CFM Max 25 25' 1475 24.65 4000 CFM Max 29 30' 1770 29.75 4000 CFM Max 35