Mini ball lock co2 regulator. Made of machined, anodized aluminum and uses 3/8″ threaded 16 gram co2 cartridges. Includes a ball lock quick disconnect. Since it has an MFL fitting, you should be able to swap that out for a pin lock QD.
This is similar in function to handheld CO2 chargers with the notable difference that it includes a regulator. The regulator lets you set a specific pressure.
Use for portable dispensing of your keg of homebrew.