Feature:1. PERFECT FIT: Compatible with for Soda DUO, for Terra, for Art machines, with this fast adapter, these three soda devices (without) can connect old blue cylinders or other cylinders with TR21 4 male threads. Of course, the adapter can help you connect the old soda hose to the TR21 4 male thread to for Terra, for Art, for Duo.2. WHAT SHOULD YOU DO: Using a quick adapter, the bottle insertion time can be very long, so it is necessary to remove the base where the 60L CO2 cylinder is located and then insert the cylinder. If you have an for Art or for Duo soda dispenser(without), please try removing the 4 screws from the base and removing the bottom, inserting the bottle, and placing the bottom back in place. If you have a for Terra Soda manufacturer (without), simply press the two pink locks and remove the pink base. It only takes a few simple steps to complete.3. EASY INSTALLATION: With just a few simple steps, your CO2 soda machine(without) can be used with this fast adapter.4. ALUMINUM ALLOY MATERIAL: The CO2 adapter is made of excellent aluminum alloy, which is corrosion resistant, durable, and safe. The surface is polished, with good sealing performance, oxidation resistance, and rust prevention.5. IDEAL REPLACEMENT: Wonderful replacement for the old and damaged parts, fine workmanship, attention to details, helps you improve the working efficiency!Specification:Item Type: Soda Water CO2 AdapterMaterial: Aluminum Alloy Thread: TR21 4Function: Connect the TR21 4 threaded soda bottle to the for DUO, for TERRA, for Art soda water machine using a quick connect cylinder.Package List:1 x Adapter 2 x Sealing Ring Note:If it is found that the TR21 4 threaded soda bottle cannot be placed into the machine when using a connector, the baffle at the bottom of the machine needs to be removed before the connector and cylinder can be placed into the machine together.