Tibet Train Oxygen Supply
The Tibet Train journey is not for everyone. For those who have trouble breathing should probably avoid the trip, regardless of the fact that there is oxygen in the cars.
Diamox (acetazolamide) us a drug that helps you with altitude sickness and should be taken with you as a precaution.
Tibet train oxygen devices:

The oxygen connectors are located beneath the seats.

Another view of the oxygen connectors.

This tubing connect to the oxygen connectors. The dual node is then inserted into your nostrils. This tubing is provided free of charge.

How to use: oxygen tube directly into the oxygen supply port interface, and then the other end of the oxygen into the nostrils, mouth.

Portable oxygen cannisters may be bought as well. These are also found in Tibet.