The QTX DMX-D8 is a DMX signal splitter that splits the DMX control signal to 8 channels and amplifies it to allow for longer control lines.
The device is fitted with 3-pole XLR connections and utilizes a galvanized optical coupler for splitting the in and outputs.
By unchaining and splitting the control signal you have a much safer, reliable set up compared to a simply chained solution. The electrical splitting protects against external voltage from switching a DMX signal between equipment (e.g. a DMX PX interface).