Optical sensors are the go-to sensor if you want a reliability over a long period of time. The Neptune Optical Sensor plugs directly into the FMM allowing you to monitor the level of your sump, mixing station, or any other reservoir that has up to 1/4" thick walls.

Includes Magnetic Mount

 This sensor plugs into your FMM and, using reflected infrared light, will signal your Apex when it changes state from being wet to dry or dry to wet. This sensor can be used for constructing your own ATO (auto-top-off), as a high-level warning sensor in your sump, water storage level sensor, and much more. The sensors can be mounted on any type of reservoir that has up to 1/4" thick walls. 

• Compatible with Neptune FMM Module
• Magnet mounts to walls up to 1/4" thick
• Can be mounted vertical or horizontal