For most applications we typically use a 3″ Sensor head which fits into any 3″ Slip Style fitting.  Regardless of which controls are used this sensor will hold all the sensor tips for all the models.  This housing and the sensor lengths can be customized for your application. We have developed custom probes and assemblies for some OEM Customers under Private Label brands.
Standard Sensor assembly: 3” diameter and approximately 20” long.

Part Number is EXT
e.g. WLC-5000-110-EXT-50  Is a 5000 Controller with an external static pipe sensor and a 50 ft wire lead on the sensor.

The external static pipe is available for those who prefer the water level control probes be in view, it is a matter of preference. The standard lengths of the sensor rods are the same as the internal static pipe: 17, 16-3/8, 15-1/2, 14 & 10-3/8. These can be cut in the field by the installer to desired lengths but normally these are acceptable.

You can also get Custom Length Sensor Rods to fit any application. The sensor tip lengths are standard lengths but can be modified as needed for your application. You can find a sensor appendix here for ordering non-standard lengths also.