How long are these devices can be used?

The use time is determined by the breathing pattern of the individual and the model of the cylinder.

For example:
1、S300 Series：About 6-10 minutes；
2、S300Plus Series：About 8-12 minutes；
3、S400 / S400Plus Series：About 12-16 minutes；
4、S500 Series：About 10-14 minutes.