NEPTUNE SYSTEMS APEX FMM OPTICAL LEVEL SENSOR V2 (OS-1) Hanna Instruments mount the blocks in air

mount the blocks in air

but it gets much closer than almost any LED available today

much of its functionality is available from the button and LED interface on its driver

Many marine aquarists only give the oxygen content in their aquarium water a passing thought

NEPTUNE SYSTEMS APEX FMM OPTICAL LEVEL SENSOR V2 (OS-1) Hanna Instruments mount the blocks in airOptical Level Sensor (OS 1) 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 into custom brackets or through a hole in a vessel. Included are a fastening nut and