This Homewerks Worldwide 1/2 in. O.D. Compression x 1/2 in. O.D. Compression x 1/4 in. O.D. Compression Brass T-fitting provides a branch outlet between a water supply valve and existing supply line. This extra male threaded connector provides an extra connection for an additional supply line or appliance connector. With this T-fitting, connecting an ice maker, dishwasher, or water filter to the existing water supply becomes a simple do-it-yourself task.