Crowcon T4 Portable Multigas Detector protects against the common gas hazards, carbon monoxide, hydrogen sulphide, flammables and oxygen depletion. TWA Resume function provides additional protection against prolonged toxic gas exposure. Positive Safety continuously assures of detector compliance. A 24-hr battery life and improved robustness increase reliability. With an invertible screen for easy viewing whilst worn, the Crowcon T4 gives you confidence however you look at it.