Compact CO2 Injector. From the description it seems like you get the injector only, so you need your own ball lock or pin lock QD.
Use to help you dispense homebrew on the go. I have a similar injector, although maybe not identical. To serve been you generally just need a couple of taps to keep the pressure at an acceptable level. Adding small amounts of CO2 as needed can help you save on CO2.
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