Amazon.com: uxcell Pipe Fitting Reducer Adapter M20X1.5 Male to 1/2 G Female, Stainless Steel for Water Oil Air Pressure Gauge : Industrial & Scientific
Metric Thread Female M20 M20x1.5 to Male M10 M10x1.0 Pipe Fitting Adapter Gauge | eBay
Male M20x1.5 to 1/2" NPT Female Adapter
M20 x 1.5 Male to 3/8” NPT Female Gauge Sensor Sender Thread Adapter