TZC-8B | Siemens Firefighter Telephone Zone Card for Desigo and FireFinder SystemsDescription The Siemens TZC 8B Firefighters Telephone Zone Card is a communication interface module designed for use in Siemens Desigo Fire Safety Modular Systems. It enables reliable voice communication between emergency response personnel located throughout a building during fire or emergency situations. The module provides eight supervised telephone zones with built in tone indicators and integrates seamlessly into compatible Siemens control