Tongo's Tape Recorder was a Telmar T-100 tape recorder manufactured by Martel in the Early 1960s. Tongo the Ape Man covertly used the recorder as a diary in his covert observations while practicing for a movie role. Speaking into it, he revealed he recognized Ginger and later deduced who the other Castaways were as well as his amazement at their creativity and ingenuity in catching him. When he gets surprised by the Orangutan and kidnapped, he accidentally drops the device which the castaways discover afterward. When they listen to the tape, they realize the mystery of his existence on the island.
- The tape recorder wasn't seen again in later episodes. It's possible Tongo picked it up in his departure or the Professor saved it as a memory device in his experiments, but this isn't revealed.
- Despite being a tape recorder, Tongo's use of it as a personal diary predates modern electronic memory devices by almost fifty years.