These VDO dip tube type fuel level sensors are available in various sizes, and are ideal to apply to foam filled fuel tanks. They are mounted through the top of the tank with a standard SAE 5 (M5) fixings on a 54mm P.C.D.
Depending on the length of the sender the resistance at empty will be between 60 & 90 Ohms and less than 3 Ohms at full
There is also an aluminium weld on tank mount available, and if the size you need is not listed, please call or email as more are available.