The Respironics EverGo Portable Oxygen Concentrator separates oxygen from room air and delivers it through a single lumen cannula. Room air contains approximately 21 percent oxygen and 79 percent nitrogen. By passing the air through a series of molecular, bacterial and dust filters, the Respironics EverGo removes nitrogen and stores nearly pure (therapeutic) oxygen.

9.9 lbs. (4.5 kg) with 2 batteries and carrying case.
8.5 lbs. (3.8 kg) with 1 battery and carrying case.

The Evergo's two rechargeable batteries provide up to 8 hours of oxygen while operating at a typical patient setting of two (20 breaths per minute). See the chart below.
Flow Setting
Rate of 20 BPM

1
12 hours

2
8 hours

3
6 hours

4
4 hours

5
4 hours

6
4 hours

The Respironics Ever Go is about the size of a camera bag or small carry on bag.

Your doctor can determine whether or not the EverGo portable oxygen concentrator is appropriate for you while you sleep. An overnight pulse oximetry test may be necessary to measure your oxygen saturation level while using the Respironics EverGo at night.