This switch is only compatible with the Radium Multi-Pump Fuel Surge Tanks (MPFST) and the Radium Fuel Cell Surge Tanks (FCST). Both of these products have specially machined ports that are labeled “Level Switch”.
20-0461 Fuel Level Switch, 1/8 NPT
This 1/8″ NPT fuel level switch should be installed inside the container, as shown below. 
When fuel level drops, a switched signal can be sent to a unit such as a dashboard mounted indicator or programmable ECU input for safety purposes. The level switch is constructed of corrosion resistant stainless steel compatible with all fuel types. It includes 24″ long, 20AWG flying leads.
NOTES:
1. Polarity can easily be reversed by removing the E-clip and flipping the float.
2. 1/8″ NPT threaded port is required for installing.
3. Always apply PTFE thread sealant to tapered pipe threads.
20-0508 Fuel Level Diagnostic Indicator
If the 20-0461 Fuel Level Switch (above) is used, this 20-0508 Fuel Level Diagnostic Indicator can be used as a visual reference for fuel level.
When the fuel level switch is triggered, the signal is sent directly to this LED.
While often not practical to be viewed while driving, this indicator can be used for diagnosing a potential fueling issue.
The 20-0508 kit includes the parts shown below. Soldering is required.
NOTES:
1. A 2AN ORB (5/16″-24) threaded port is required for installing.
2. If stacking on top of the fuel level switch (as pictured above) the panel thickness must be 0.75″ minimum.
20-0519 Fuel Level Switch Plus Indicator
This kit simply combines 20-0461 and 20-0508. For more information, see above.
