A transfer gearbox (or transfer case) is a system of gears or an auxiliary transmission, used in four-wheel drive vehicles, which transfers torque from the transmission to the front and rear driveshafts. Transfer gearboxes typically have two gear ranges, High and Low. high Range is used for typical on-highway or light off-road use. Low Range is used for serious off-road conditions. Putting a transfer gearbox in "Neutral" disconnects the transmission from the wheels. Unless the brakes are applied (foot brake or hand brake), a vehicle can roll when the transfer gearbox is in "Neutral", even if the transmission is in "Park" (automatic) or a forward/reverse gear (manual).