From the actual product website -- www.winekeeper.com:
"Small, inexpensive, yet capable, The Keeper brings quality wine preservation to any setting. Keep your wine fresh for weeks while saving space, and choose from Nitrogen or Argon to preserve the wine."
 
Own the same system that restaurants use to serve wine by the glass. Wine can be preserved by adding harmless inert gas into open bottles to displace oxygen, which causes wine to spoil. 
 
Includes two wine stopper/faucets and a single-stage regulator. Wine and gas canister are not included. 
 
You may purchase canisters of nitrogen or argon gas at local shops by Googling < wine making columbus ohio >
or at https://www.winekeeper.com/refills-parts-wk/refills-parts-gas-cylinders. 

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