Liquid-filled pressure gauges are more durable than dry gauges because the liquid dampens vibration and pulsation often experienced in high-performance boating and racing. 
 
The liquid also lubricates the gauge's moving parts reducing corrosion and friction; withstands lower temperatures down to -40 degrees Fahrenheit. 
 
The Buckshot Racing low-pressure (0-15 psi) Fuel Pressure Gauge + Billet Adaptor is a great match for carburated outboard applications with electric fuel pumps.
 
This billet aluminum 3/8" in-line adaptor (currently available in blue) allows for easy installation.
 
For most applications, it's recommended to be placed after the fuel pump to help ensure you have 4 - 8 psi of fuel pressure going to your carbs. (tank>filter>fuel pump>Fuel Pressure Gauge + Billet Adaptor>filter>carbs)
 
Included one (1) Fuel Pressure Gauge + Billet Adaptor