Black tees connect (3) same-size (equal) or different-size (reducing) black pipes together. The proper way to read a Tee fitting is Side x Side x Middle (Top). When a tee has only (2) sizes in a description, the former latter to the Middle (Top) outlet, i.e. 3/4" x 1/2" tee is a 3/4" x 3/4" x 1/2" tee.
