without adapter: you can use it without adapter.Aluminum and plastic: This CO2 charger is made of aluminum and plastic. This implies higher quality and durability.Convenient Setup: 8mm bar in disconnect position, attach to your keg and adjust dose pressure with CO2 line.European standard: It corresponds to European Soda Stream standard. Used for carbonated water bottles with T 21*4 thread.Premium Regulated Charger: It is very compact but is just big enough to accommodate a very small regulator.Product Description Do not use an adapter. Made from aluminum and durable plastic. Superior quality and durability. 8mm bar on disconnect, attach to your keg and adjust the dose pressure with the CO2 line. Suitable for European Soda Stream Standard. Used for carbonated water bottles with T 21*4 thread. Premium Regulated Charger is very compact, but is just large enough to accommodate a very small regulator. Specifications: Condition: 100% brand new Material: Aluminum, Plastic Color: as shown in the picture Size: Approx.8*6.1cm/3.2*2.4in Thread: T21*4 Package List: 1 * Gas Regulator