These adapters will allow you to fit Wema Flanged (SSS) or Threaded (S3U) Tank Sensors to your water, fuel, or waste tanks.
This can be done as a replacement of an existing SAE sender, or as a new installation.

The FL-2WE Top Adapter (for outside the tank) mounts on top of the tank, and is threaded to accept the S3U Threaded Sensor, which has BSP threads.
It comes with a gasket, and has two bolt patterns: an SAE 5-hole (inner pattern), and a European standard 5-hole (outer pattern).

The FLS-U Under Ring Adapter (for inside the tank) has threaded metal inserts in an SAE 5-hole pattern.

To Install a Threaded Sensor:
To install an S3U Threaded SAE Tank Sensor, you will need the FL-2WE Top Adapter, which will match up with the existing threaded holes in your tank
For a new Threaded Sensor installation, you will also need the FLS-U Under Adapter, which will provide the necessary threaded mountiing holes

To Install a Flanged Sensor:
To retrofit an SSS flanged tank sensor (which comes with a gasket), you will not need an adapter, as your tank will already have the required threaded mounting holes
For a new flanged sensor installation, you will need to use the FLS-U Under Adapter to provide the necessary threaded mounting holes