HelixNet Main Stations accept linking as well as two-wire and four-wire optional interface modules, offering seamless connectivity to LAN and virtually all common two-wire and four-wire audio systems. The HLI-FBS Fiber Linking Module provides a daisy-chain fiber interface to connect to other HelixNet Main Stations. Up to three stations can be connected together. With Fiber Modules, stations share partyline channels and program audio, and make them available to any station and beltpack on the linked system. Fiber Modules can be mixed with Ethernet Modules in the same network. The HLI-FBS has two slots but comes with one single-mode transceiver fitted. The second slot can have an optional HLI-SMFO single-mode or HLI-MMFO multi-mode transceiber fitted before or after leaving the factory.