The display is small and very dark The display is small and very dark, virtually invisible. Therefore there is no use for this instrument. I am very disappointed, and I would return it to you for full refund. Please send me instruction or procedure how to proceed the return

No contact after sale. No contact after sale. Amber light is on constantly and worrisome. Don’t know how to fix it. No one has contacted me.

Terrible Terrible. No way to contact if need to return merchandise. Have phoned and it just rings. Have left 2 emails plus 1 messenger message. No response!!! Will not forget the name of this company and how unprofessional they are.

Oxygen recovery therapy The unit is almost perfect except for the oxygen concentration levels at higher liter/minutes decrease significantly. So anything above 3 liter/minute reduces total oxygen per breath cycle. But at this price it’s great.