This adapter is designed to split the Composite sync so that a workstation that only has the composite sync signal (no H/V signal) can be connected to a VGA monitor that only supports the H/V signal.Some older SUN and MAC workstations have the composite sync and don't provide the H/V signal. This adapter was designed to allow a VGA monitor work with those workstations.This adapter would not be necessary for newer SUN and MAC workstations that provide the H/V signals.