How to choose a portable oxygen concentrator?

How to choose a portable oxygen concentrator? Which brand of oxygen concentrator is good? Maybe you know Inogen ,Philips simplygo mini,Airsep Freestyle.etc. But here is a reliable oxygen concentrator brand, Longfian.

As a consumer,we want a portable, safe and simple oxygen concentrator.Longfian oxygen concentrator meets all the features you want.

I.It has mini size and light weight only 1.98kgs and rechargable battery up to 5.5 hours.

II.Longfian oxygen concentrator is Safe，efficient and low noise.

Longfian Scitech Co.,Ltd, a leading manufacturer specialized in oxygen solutions for 25 years,and has its own factotry.If you urgently want a portable oxygen concentrator,Longfian oxygen concentrator will be arrived to you as soon as possible.

It is the best choice for hypoxic patients when you go out for activities,travel or emergencies.And it is also a perfect companion when working and traveling on the plateau above 2000 meters.