Features 1、Good Performance: Excellent manufacturing, stable operation and high reliability, on the other hand, sturdy design and manufacturing will last for a long time. 2、Fine Workmanship: Small size, light weight, easy to carry and store, convenient to use, conversion from TR21‑4 to CGA320. 3、Excellent Material: The pressure relief valve is made of premium aluminum material, which is sturdy, durable, and has a long service life, making the portability of homemade beer easy. 4、Easier Refilling: This is a great accessory, so you don't have to drag around larger containers due to the small size of the carbon dioxide container. This is not recommended for carbonization, but it is very good for distribution. 5、No More Leakage: Widely applicable to various soda bottles with CGA320 connector, the soda refill adapter ensures no leakage during the refilling. Specification Item Type: Soda Refill Adapter Product Material: Aluminum Alloy Product Application: For Tr21-4 to CGA320 conversion. Package List 1 x Soda Refill Adapter