Product Description Nutlock Reducer Coupling 20mm – 16mm Nutlock fittings for easy and water tight connection. Materials: Body and nut PP, Grip PBT Threads: BSPT Max. working pressure: 10kg/cm2 Fertilizer resistant All 16 sizes fit also 17 sizes Wall thickness: 16-17mm: 0.7 1.5mm, 20mm: 0.9 2.0mm, 25mm: 1.4 2.0mmAll nut lock fittings are available in American 1/2 (16-18mm) pipe diameter.