The automatic release is used to free the rope from the pulley at the right moment to allow the log to finish its path parallel to the trail, without having to interrupt the operation to remove the rope from the pulley. When the trigger hits the open-face pulley, its diameter ejects the rope, allowing the log to pivot along the trail and continue its path straight towards the winch or pulling vehicle.
This accessory greatly improves the productivity of small-scale foresters.