Description: High quality material, durable and never fade. Fully automatic high-precision CNC lathe processing. Standard interface , neat thread , bright appearance. Durable, easy to change and connect between the pipes. Variable diameter joints can achive all kinds of plumbing and pipe connections, telescopic, compensation, displacement etc. Size Chart: #1 Outer diameter:20mm/0.79inch Thread length:12mm/0.47inch Length:51mm/2.01inch Width:39mm/1.53inch #2 Interior Diameter: Approx. 19mm/0.75inch Outer Diameter: Approx. 20mm/ 0.79inch Thread length:12mm/0.47inch Length:49mm/1.93inch Width:35mm/1.38inch #3 Interior Diameter: Approx. 19mm/0.75inch Thread length:16mm/0.63inch Length:47.6mm/1.87inch Width:34mm/1.34inch #4 Interior Diameter: Approx. 19mm/0.75inch Outer Diameter: Approx. 20mm/ 0.79inch Thread length:11mm/0.43inch Length:44mm/1.73inch Width:39mm/1.54inch Package Includes: 1 Piece Brass Coupler Connector (3 Pack) Note: As different computers display colors differently, the color of the actual item may vary slightly from the above images. There is 2-3% difference according to manual measurement. Please check the measurement chart carefully before you buy the item. Methods: 1. Remove impurities in pipe and joint before taking over. 2. In order to make a better sealing, it is recommended to use the rubber tape at the thread connection to make it more sealed and impermeable. 3.Tighten the threaded pipe joints, should pay attention to the appropriate tightening torque.