optical rain gauge series is a reliable and cost-effective choice for precipitation measurement. The overall size of the optical rain gauge is about the size of a tennis ball, and the internal sensor is completely sealed from the external environment. The delivery comes with mounting brackets that can be easily installed on weather stations, street lights and other infrastructure. Working principle: When raindrops pass through the sampling space, the raindrops block the laser, and the light signal received by the receiving sensor and the electrical signal (such as voltage or current) converted from the light signal change. When the raindrop passes through the sampling space, it receive the electrical signal from the sensor. Restore the previous state. When the raindrops the sampling space, the electrical signals of the receiving sensor are processed, and the time for the raindrops to the sampling space can be obtained. Colour:Transparent Material:ABS Package Contents: 1 x Optical rain gauge Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.