Enjoy excellent sealing performance with no air leakage when connected to the cylinder, making it more convenient to use. Primarily used for the thread adapter on soda machine cylinders, and can also be used as an air source switch. Crafted from high-quality materials, offering high hardness, wear resistance, and a long service life. The thread is tight, showcasing superb technology, stable performance, and easy installation and use. If you want to use a SodaStream TR21-4 soda water bottle instead of a Quooker Cube bottle, this adapter is the perfect solution. Threads: Tr21-4 female to Tr12-3 male. Note: The product is subject to continuous updates. Due to different batches, the actual product may have slight differences or color variations, which will not affect its use. Color: Photo color Material: copper Package Contents: 1 x Soda CO2 Gas Converter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowable measurement error is +/- 1-3 cm.