The M983 is a tractor unit for use with the trailer-mounted MIM-104 Patriot missile system. It can also be used with the Interim Stryker Recovery System, or other trailers.^[12][15] An earlier variant fitted with a 30 kW generator and crane mounted behind the cab was used to tow the Pershing II Erector Launcher in CONUS (a M1001 MAN tractor was used in West Germany). The M983A2/A4 Light Equipment Transporter (LET) tractor is mainly used to transport construction and engineer equipment. It has a 45,000 lb (20,000 kg)) 2 speed hydraulic winch mounted behind the cab used to load the trailer. It does not have a self-recovery winch.^[7][16]