Oxygen concentrator
How it works: Takes room air → filters nitrogen → gives 90-95% pure oxygen. Runs on electricity, no refills.
Specs: 1-10 LPM flow. Stationary = up to 10LPM. Portable = 1-5LPM + battery 4-10hrs.
Use: Home/hospital for COPD, pneumonia, low O2 saturation.