Soda CO2 Gas Converter Adapter for TR21-4 Female to TR21-3 Male Thread Copper Tank Output Good sealing performance, no air leakage when connected with the cylinder, more convenient to use. Mainly used for the thread adapter of the soda machine cylinder, and can also be used as an air source connector. Made of high-quality copper materials, durable, high hardness, wear-resistant, long service life. The thread is precise, with excellent craftsmanship, stable performance, and easy installation and use. Allows the use of a soda bottle with TR21-4 thread in place of a compatible system; enables connection between different thread types. Threads: TR21-4 female to TR21-3 male. Note: Product design may vary slightly between batches. Such variations do not affect functionality. Color: As shown in photo Material: Copper Package Includes: 1 x Soda CO2 Gas Converter Adapter Content limited to the above; other items not included. Note: Lighting and monitor settings may cause slight color differences between the image and the actual item. Measurement error allowance is +/- 1-3 cm.