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 technology, stable performance, and installation and use are simple. Compatible with sodasteam TR21-4 soda bottles as an alternative to Quooker Cube bottles. Threads: Tr21-4 female to Tr12-3 male. Note: Product may vary slightly between batches; slight differences or color variations may occur but do not affect functionality. Color: As shown in photo Material: Copper Package Contents: 1 x Soda CO2 Gas Converter Only the above package content is included; other items are not part of this package. Note: Light reflection and different displays may cause the color of the item in the picture to differ slightly from the actual product. Measurement error allowance is +/- 1-3 cm.