System of synchronized transmission found in modern gearboxes to make gear changing easier and smoother
{i} gear system that synchronizes the gears to make facilitate gear-shifting (Machinery)
(Otomotiv) A manual transmission device that allows two gears to mesh more smoothly by causing them to spin at the same rate of speed before coming together
an automotive system for shifting gears in which the gears revolve at the same speed and so shift smoothly