For single-point grounding, 4-port Sure/Fire blocks or hubs can be stacked vertically and horizontally for virtually unlimited number of surge protected devices. Blocks easily interconnect for port expansion and install into various mounting situations. Faceplates may be color coded to define type of phone line, data interface, and LAN or I/O signal connection. Sure/Fire comes with RJ45, terminal block, DB9, DB25, and various coax style connectors.