Brass material: The adapter is made of high-quality brass with good wear resistance, ensuring durability and airtightness of the connection, suitable for long-term use. Easy installation: This cylinder conversion adapter requires aligning the threaded connection when attaching to the gas bottle. Tighten by hand first, then moderately with a wrenchavoid over-tightening to prevent damage to the sealing ring. After installation, slowly open the gas source and check for leaks to ensure proper function. Working pressure range: The adapter supports a working pressure up to 3000 psi (207 bar), significantly higher than the typical 100120 psi required by home soda machines, allowing safe and stable inflation under controlled high-pressure conditions. Thread size: 1 x thread conversion adapter (TR21-4 female to TR21-3 male). Enables compatibility between TR21-4 threaded bottles and compatible systems. Please verify thread specifications before purchase. Wide application: This CO2 brass cylinder adapter fits most TR2 standard CO2 cylinders available on the market (confirm bottle thread type prior to use) and serves as a practical accessory for compatible systems. Its compact design also makes it suitable for outdoor use. Color: Yellow & Red Material: Metal Package contents: 1 x connector with cap Note: Light reflection and differences in display screens may cause slight variations between the color shown and the actual product. Measurement may vary by +/- 13 cm.