Continuous work after mains interruption ,O2 Supply Speed 35L/min~75L/minSigh Volume not less than 1.5 times of Tidal Volume , Upper airway pressure limit 1. 0kPa~5.4kPa ,Lower airway pressure limit >0.5kPa I:E 1:0.5, 1:1, 1:1.5, 1:2.0, 1:2.5, 1:3.0 Max pressure