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 the air source switch. Made of high-quality materials, high hardness, wear-resistant, long service life. The thread is tight, advanced manufacturing technology, stable performance, and simple installation and use. Suitable for using a sodasteam TR21-4 soda bottle instead of a Quooker Cube bottle. Threads: Tr21-4 female to Tr12-3 male. Note: Product may vary slightly between batches; actual product may have minor differences or color variations, which do not affect functionality. Color: as shown in photo. Material: copper. Package includes: 1 x Soda CO2 Gas Converter. Other items not included. Light reflection and display settings may cause slight color differences between image and actual item. Measurement error allowed: +/- 1-3 cm.