Accurate: [Fitting Size] AN16 (Female) to AN12 (Male) Flare Reducer Fitting Adapter. Male Inner Diameter: 13.9mm / 0.55", Female Inner Diameter Material: Made of 6061-T6 aluminium alloy. Max working pressure: 1500PSI,working temperature: -40°F to 250°F. It is highly recommended to use sealant or PTFE (polytetrafluoroethylene tape) at the NPT port. Gauge Port Fitting Fuel Tank Bung Fitting EVIL ENERGY 12AN Female To 3/4 NPT Male Swivel Fitting 3/4 NPT Female Fitting Aluminum AN Fitting Fuel pressure take off fitting: AN12 Male to -12 Female with 1/8 NPT Gauge/Gage Port,the thread size of the 12AN is 1-1/16-12 UNF. Size: AN12 with 1/8 NPT Port. Thread Type: NPT. Connector Type: Flare EVIL ENERGY provide 12an fuel pressure gauge fitting 3-month warranty. Include:Fuel System Exhaust、System Cooling System. Black Anodized AN Fitting 8AN To 1/2 Barb Fitting Adapter - Aluminum Fuel Line Connector, Black Anodized Aluminum Hose Barb Connector Any problem you might have,please feel free to contact us via Amazon message.