Tee, elbow, joiner, with barbed ends. Aquatic fittings for connecting standard vinyl and soft PVC tubing for canister filters, reactors, protein skimmers, calcium reactors, etc. Also for connecting the water return lines for sumps and recirculating pumps. Hose slips onto barbed end for secure fit in 1/2, 5/8 and 3/4 inch ID tubing.