The double O-rings design of these fittings significantly better sealing than traditional single O-rings designs Make from highly strength Copper and Metal, these 3 / 4inch elbow fittings are builted to bear highly pressure environments It ensures a seamless connection within your existing compressed air systems The 90 degree bend allows for flexible installation and direction adjustments, making it easily to navigate around tight spaces or complex piping layouts Specifically designed to fit 3 / 4inch tubing and is fit for Compressed Air Line Tube systems Kits, Manufacturer: Dezzhou