With the inclusion of a double limb circuit, 2 extra therapy programs, and the options of sigh breath or manual breath therapy, Astral 150 delivers even more capability. A device with Single limb and Dual limb circuit both, (With Battery backup (Battery life 6-8 Hours) "Ventilation mode: Valve circuit therapy : CPAP, ACV, PACV, P-SIMV, V-SIMV, PS ; Leak circuit therapy : CPAP, ST, PAC." Manual breath function and sigh breath is available Dual limb tubing, exhalation valve, O2 port, power cord