Soda CO2 Adapter Hose Kit TR21-4 CO2 Cylinder Refill Station Filling Adapter
If the small bottle thimble is very thick, and it will be inflated difficulty, need replace thin thimble bottle. CGA-320 /W21.8 CO2 Cylinder Refill Adapter Bottle Connector CO2 Tank Soda Maker Accessories with Hose for Filling Soda Tank.