The Sanyo RD-4025 is a stereo cassette deck manufactured by Sanyo between 1976 and 1978 in Japan. It features a sleek design with a silver and black finish, complemented by a Plexiglas dust cover for protection. At the time of its release, the RD-4025 was priced at approximately 400 DM. The device is part of a series that includes other models like the Sanyo RD-4055 and RD-4080, indicating a range of offerings in cassette deck technology during that period.