The PortaCom B3-100 Branch Box was designed as a beltpack expander for the COM series of wired intercoms The B3-100 is a small, lightweight box with an XLR input and 3 XLR outputs, enabling connection of 3 beltpacks for additional crew personnel. It draws power from the PC-100 system powering console, and may be daisy chained to accommodate up to 20 BP-200 system beltpacks.