A slightly larger version of the popular GP9, the SD9 provided extra pulling power, and could also be ordered in a lightweight version for use on branchlines. Many are still in service today.
 
These revised models now feature full front and rear pilots, a DCC-ready frame, golden-white LED directional lighting, blackened wheels, ScaleSpeed(TM) motor, low-friction drive, dual brass flywheels, and factory-installed AccuMate(R) knuckle couplers. Models are offered with or without dynamic brakes to match prototype practice.