Colorado Altitude Training altitude generator and tent.
Tent for queen sized bed. One door. Tubing with canister quickly gets to high altitude by recirculating air. Once at desired altitude, put tubing with canister out of tent to scrub down ambient air and keep tent at desired altitude. Generator stays out of tent which is quieter for sleep and cooler without the heat of the generator in the tent. Put canister in window to blow cool, low-oxygen air into the tent.
Awesome system. Limited use. Just don't need it.
Great for endurance athletes, mountaineers, and adventure enthusiasts.