1.5" TC x BarbNot all hose barbs are created equal! Our special 1. 5" TC x barb fitting features a shorter profile and over sized diameter barb. The over sized barb (5 8" OD) is specially designed for our 1 2" Silicone tubing (seen HERE). The larger size does two things: 1) It stretches the tubing over the barb creating a tight fit requiring no hose clamps. 2) The inside diameter of our barb is 1 2" compared to standard 1 2" barbs which have a smaller 3 8" size.