I will soon be taking the state exam to get my license. On the material list is a "90 degree twin elbow". Am I missing something? I don't know what fitting they are talking about. A little help would be much appreciated. Any ideas?

Mike, send this one to Speedball1, he's at the other end of a plumbing career. He is near the top of the members list. I have never heard of a twin elbo but if it exists Speedball1 will have the dope.

A twin ell is an elbow that is 90 degrees and goes in a wall between two lavatories that are back to back. It has 2 inlets and one outlet. You can pick up both lavatories from the same fitting. I do not suggest using it though. It is troublesome to use a cable to clear the drain.