PCB Mounted MQ-3 Tester Kit with Adjustable Sensitivity RW Potentiometer

Portable Alcohol Testing Kit with MQ3 Sensor for Personal and Professional Use

Alcohol Sensor MQ3 Module Kit for DIY Alcohol Detection and Control System

PH Tester Monitor PH Electrode Probe 0-14PH 0-80��C 100cm High Sensitivity

Microphone Sensor Adjustable Amplification Onboard Potentiometer Home Automation

Adjustable Sensitivity Metal Detector for Customized Scanning of Metals