This was an old link . . . and a special price.
Most places sold this unit for $150+ not including shipping charges.
---------------------------------------------------------
The installation is real easy
Just like franco said it's an inline sensor.
you cut the fuel line b/w the tank and the fuel/water seperator (if you have one) - navman recommends that you find a section where the sender can be mounted in a vertical position .
Install the inline the sender with two hose clamps and run the wire from the sender to your dash. The gauge is 2" . . . . so you can rip out the old fuel tank gauge and put in a fuel flow meter. Then you just need to power the gauge (12v +/-) .