This is a new, replacement pressure relief valve that fits most Cornelius-style soda kegs. A pressure relief valve is designed to allow excess pressure to escape from your soda keg. The excess pressure will automatically escape if the pressure level in the keg becomes too high. From time to time these valves can become worn and need to be replaced. You simply unscrew the old one and screw the new one in. This can normally be done by hand.
The new, replacement pressure relief valve should last you for many, many years.
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