These locos will be available with or without factory installed QSI Quantum sound and DCC with dual speakers. The hefty die cast chassis will ensure maximum tractive effort for the skew-wound balanced-armature, dual flywheel equipped locomotive. Units with dynamic brakes will have visible resistor grids in the radiator screens. Features include: - Sounds include diesel engine, horn, bell, squealing brakes, doppler effect, air letoff (in neutral). - Sound can be operated with a standard DC power pack as well as DCC controllers. - Precisely machined worm gear and spur teeth provide silent running