2pcs 3/8" NPT to M18 x 1.5mm Male Straight Air Hose Fitting Connector Adapter | eBay
M18 x 1.5 (male) to 1/2" NPT (male) Thread Adapter: 316 Stainless Steel
Car Oxygen O2 Sensor Adapter CEL Fix Check Engine Light Eliminator M18*1.5 - Walmart.com
Parker M18-1/2F8Ohgs M18X1.5 Male Metric X 1/2" Fem Npt
Amazon.com: 10AN Flare to Metric 18 x 1.5mm Pipe Hose Adapter Fitting Aluminum Black Anodized AN10 Male Flare to M18-1.5 mm Male Metric Thread : Automotive
Redhorse Performance -10AN Male AN Flare To M18 x 1.5 Inverted Adapter