Usually they are mostly home made from a local supplier, mainly being glass cages with inlets and outlets for gases and/or additional probes. The chamber is then continuously flushed with a gas mixture to attain the desired level of hypoxia. It doesn´t really need any special characteristic besides the size and the absence of leaks, and it will get probably much cheaper than getting it from one of the pharmaceutical companies.

I agree with Dr. Prieto-Lloret - if you're doing it on the cheap, a glass or plexiglass box with an inlet and a flush will cost almost nothing to build - maybe $30-$50 each. I used to use those all the time (you usually buy several). You just buy the gas mix you want, and flush it with it. If you've got $10,000 to blow, you can buy a beautiful commercial glovebox. And there are all stages in between.

As low as $11 to $119. The best technology. Disposables, cell regulated. From Celartia Ld.

http://www.celartia.com/stores/index.php/hypoxia-chambers.html

I wrote an article that you may help you consider the measurements your next hypoxia chamber or workstation uses. It compares chambers that use absolute measurements vs those that use relative ones. When you do go out and look for a chamber it should inform you to some of the questions you may want to be asking. Give it a read here:

https://www.oxford-optronix.com/resources/the-reproducibility-issue-within-hypoxia-chambers-and-a-simple-solution-to-fix-it

If you are looking for a glove box style system the one I would recommend looking at is the HypoxyLab. Its the only system taking measurements using partial pressures of O2. This just means it will be more accurate day to day and for comparing to the in vivo experience.

https://www.oxford-optronix.com/en/Hypoxia-Workstation

Hope that helps,