Emergency telephones for utility tunnel purpose made of aluminium alloy material by die casting. The telephone waterproof is rugged and durable. Body-integral, Strong flame retardancy and low-temperature resistant. Special sealing design can ensure complete waterproof grade up to IP66. Waterproof, dustproof and moisture-resistant. The telephone waterproof widely used in tunnel and outdoor. Most metro and high-speed rail project need install IP66 telephone for emergency communication.