Four-in-one gas detection High-sensitivity intelligent multi-gas detector with digital LCD display that directly indicates the concentration of four gases. Each detector is factory calibrated. Ready to use right out of the box. Four alarm modes This portable four-gas monitor has four alarm modes (sound, light, vibration and display), which is convenient for use in confined spaces and alerts you when dangerous gases are detected. Compact size design with a stainless steel clip on the back that can be easily clipped to clothing, pockets or belts, ensuring you can work safely and comfortably in limited spaces. Wide application This handheld gas meter tester has a compact size design and is easy to use. IP65 is widely used in explosion-proof, waterproof, and dust-proof environments.