The WM-7 was Sony's first auto reverse Walkman. Featuring logic controls and 3 motors. It also allowed for a remote control for the functions. Other features like Dolby B noise reduction, tape type selection and a Hold button were also included. Coming in two colors, silver and black. Black seems to be the rarer one. It uses two AA batteries and uses a dc to dc converter to help power the Dolby noise reduction system as the AA batteries were not powerful enough to power the Dolby circuit.