UP100 Portable Co2 Keg Charger & Ball Lock Gas Fitting HomeBrew Beer for Party Kegs Pocket-sized Cornelius Keg CO2 Charger is the ideal tool for any home brewer using Cornelius kegs Press the trigger to release CO2 into the keg Release trigger to stop flow Save remaining CO2 for later use Made of high strength, glass-reinforced nylon, with brass valve internals.