without adapter: you can use it without adapter. Aluminum and plastic: This CO2 charger is made of aluminum and plastic, which means increased quality and durability. Convenient installation: 8mm bar in disconnected position, attach it to your keg and adjust the dose pressure with the CO2 line. European standard: It corresponds to the European Soda Stream standard. Used for carbonated water bottles with T 21 * 4 thread. Premium Regulated Charger: It's very compact but it's just big enough to accommodate a very small regulator. Product Do not use an adapter. Made from aluminum and tough plastic. Superior quality and durability. 8mm bar at the disconnect, attach it to your keg and adjust the dose pressure with the CO2 line. Fits European Standard Soda Stream. Used for sparkling water bottles with T 21 * 4 thread. The Premium Regulated Charger is very compact, but it is just large enough to accommodate a very small regulator. Specifications: Condition: 100% brand new Material: Aluminum, plastic Color: as shown in picture Size: Approx. 8 * 6.1cm / 3.2 * 2.4in Thread: T21 * 4 List of packages: 1 * gas regulator