Brass material: The adapter is made of high-quality brass, offering good durability and wear resistance, ensuring a reliable and airtight connection suitable for long-term use. Easy installation: This cylinder thread adapter allows for straightforward setup. When connecting the gas bottle, align the threaded connection, hand-tighten first, then moderately tighten with a wrench without over-torquing to avoid damaging the sealing ring. After tightening, slowly open the gas source and check for leaks to ensure proper function. Working pressure range: Designed to handle pressures up to 3000 psi (207 bar), well above the typical 100-120 psi required by home soda machines, providing safe and stable performance within standard operating 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 bottles 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 in the image and the actual product. Measurement tolerances are within +/- 1-3 cm.