"Made from solid brass (unpolished). This elbow fitted 15mm copper tube like it was made for the job. The head of the lock nut fitted the spanner as if they were long lost friends. If you have two peices of copper at 90 degrees to each other and want to join them without using heat then this compression fitting is an ideal solution. However if the peices of copper are in line with each other, then a staight coupler may be the solution you are looking for."