TurboJet Max ll Negative Air Duct Cleaning Machine Dual Speed, 3-Phase Motor The TurboJet Max II negative air machine is a compact workhorse for residential and light commercial duct cleaning. It’s hard to believe a 20” wide cabinet can provide 2700 CFM at 5” static pressure, a full-size 12” inlet, 3-stage HEPA filtration, soft start and will run at 13 or 17 amps and has a 3 year warranty. This is performance that is found in units tw