Used CM3500 – 20″ airlock by Barry Pendley | Jan 24, 2019 | Used Insulation Blowers & Machines Cool 3500 with 20” airlock, (about 9 years old) (4000 lbs/hr cellulose) 5hp PD Blower, 50 Amp 240 volt Input 4″ Hose Output NEW PRICE = $16,411 USED PRICE $10,500 With 90 day warranty. (Shipping not included) Favorite Sections on this Site