Telephone equipment and communication devices used for voice communication, data communication, and emergency contact systems in manufacturing sites. Includes factory internal phones, business telephones for field workers, communication systems between production lines, explosion-proof telephones for emergency contact, IP telephone systems, intercoms, private branch exchanges (PBX), and wireless communication equipment. Products are centered on dust-proof, waterproof specifications and vibration-resistant performance to handle harsh environments specific to manufacturing. Also covers communication infrastructure equipment necessary for integration with production management systems and establishing contact systems with quality control departments.