The ALTAIR 4X is a reliable, state-of-the-art multi-gas meter that measures O2, H2S, CO, and flammable and combustible gases.This portable Quadruple gas meter simultaneously measures flammable and combustible gases (hydrocarbons), Oxygen, Hydrogen Sulfide, and Carbon Monoxide. It also features a standard built-in personal inactivity alarm that provides rescue in the event of inactivity (fainting, poisoning, etc.). The ALTAIR 4X's robust design withstands drops from 6 meters. Its high-contrast display and large buttons make it user-friendly and easy to use even in low light conditions. It features a visual, audible, and vibrating warning system. It can store 500 events in its internal memory. It is covered by a 3-year warranty. ATEX II 2G EEx ia D IIC T4. This portable gas meter can measure 4 gases simultaneously in various industrial applications such as chemical, mining, oil and gas, wastewater treatment, pharmaceuticals, fire departments, and more.