ZF AS Tronic is an automated manual transmission made by ZF Friedrichshafen for the bus, motorcoach and lorry market in Europe and North America. It was first introduced in 2003. As is the case with most automated-manual transmissions, it lacks the torque converter that is standard on conventional automatic transmissions. The AS Tronic is claimed to be 500 pounds less than the ZF B500 torque-converter conventional automatic transmission range.