Life-O-Gen Portable Emergency Oxygen Units No first aid station is complete without emergency oxygen - it can sometimes mean the difference between life and death. Single unit system has one 15-minute disposable U.S.P. oxygen cylinder. Comes complete with fixed flow (6 LPM) regulator, oxygen mask with seven feet of tubing and one-way resuscitator valve mask. Twin Pack comes complete with accessories listed above and two 15-minute oxygen cylinders conveniently packed in an impact-resistant carrying case.