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 thread conversion adapter requires alignment of the threaded connection when attaching to the gas bottle. Tighten by hand first, then moderately with a wrench. Avoid excessive force to prevent damage to the sealing ring. After tightening, slowly open the gas source and check for leaks to confirm proper function. Working pressure range: The adapter supports a working pressure up to 3000 psi (207 bar), significantly higher than the typical 100–120 psi required by home soda machines. It allows safe and stable control within high-pressure applications. Thread size: 1 x thread conversion adapter (TR21-4 female to TR21-3 male). Enables compatibility between TR21-4 threaded bottles and compatible systems. Verify thread specifications before purchase. Wide application: This CO2 brass cylinder adapter fits most TR2 standard CO2 bottles available on the market (confirm bottle thread type prior to use). Ideal for users requiring connectivity with 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 display differences may cause slight variations between the product color in images and actual item. Measurement may vary by +/- 1–3 cm.