Description: Use imported groove coupler sensor The groove width of 5mm. Output status indicator, the lamp output high, output low lights. Obscured output high; unobstructed output low. The comparator output, the signal is clean, the waveform, driving ability, more than 15mA. Operating voltage 3.3V-5V The output in the form: Digital switching outputs (0 and 1) A fixed bolt hole for easy installation Small plates PCB dimensions: 3.2cm x 1.4cm Using a wide voltage LM393 comparator Specification: Material: Plastic Size: Approx. 35*15mm / 1.38*0.59inch Module using the instructions: 1. Module slot unobstructed, receiver tube conduction module DO output low, shelter, DO output high; 2. Module DO connected to the relay, composed of the limit switch functions can also be connected to the active buzzer module, composed of the alarm. Package Includes: 1 x Sensor Module