4 Gas Monitor Multi Gas Detector Sound Light Shock 4 Gas Meter Tester Analyzer Rechargeable Portable Gas Detector Product description Dear friend, Welcome to GEALDEN, Our Handheld Multi Gas Monitor is definitely the right choice to protect you and your family’s health and property GEALDEN is a business company specializing in the development, production of gas detectors, All of our products are in high quality but very competitive price Our multi-gas detector used advanced integrated circuit technology, embedded microcomputer control, high quality imported gas sensor, It has excellent sensitivity and excellent repeatability 100% KEEP YOU SAFE Our 4 Gas Detector comes FACTORY CALIBRATED, Open and use directly. It has super high sensitivity, excellent repeatability, accurate measurement, and quicker response time(