The model 587 is a five tube, single band superheterodyne that operates on either 6V DC or 110V AC. This set was designed to appeal to people in rural areas, beyond the reach of electrical lines. Many of these people were putting off the purchase of new battery sets because they expected the electrical lines to reach their homes in the near future. This set appealed to them because it could operate off of a single 6V battery or, with the turn of a switch, on AC.