Home / Agriculture / Reducing Coupler Reducing Coupler Size Choose an option16mm X 13mm20mm X 16mm16mm X 13mm20mm X 16mmClear Related products Hydroponic 4″ X 2″ Rectangular Pipe 47mm Garden Tray – 40 holes LDPE Tubing Pipe RAINDRIP Tap Timer Hydroponic 4″ X 2″ Rectangular Pipe Socket Hydroponic 4″ X 2″ Rectangular Pipe Elbow 90deg