ResOne High Flow Liter Meter Pen: Measure Oxygen Flow Rates 2-15 LPM - Compact Oxygen Flow Meter for Quick, Precise Flow Checks

Does exactly what it's described to do. Wanted a measure just to have for our oxygen machine and saw the original tech who installed it had one. Easy to read and works perfectly.

This little pen is easy to use and is accurate

I used this to check the oxygen from my concentrator to the end of the tubing which was 50’. Levels stayed very close.

It’s good at measuring flow of air from an oxygen concentrator that has continuos flow. It’s more difficult on a unit that has a pulse delivery flow, because the pulse of air flow is very quick. It will briefly move the stainless ball, but not as far as a continuous flow unit. The value is good if you are just wanting to know that it is delivering air.

As an oxygen user, it's a simple, handy and convenient way to check the flow. Lets me compare the flow at the tube end with the numbers on the concentrator.

It works rather well and accurate. I am a COPD patient and use O2 a lot during each day.

I use it for my hydrometer testing, great tool

keep track of air for oxegen

Works as described and very accurate with Continuous flow hose, But does not work well with Pulse Flow as it is intermittent flow and does not read properly.