I think you're thinking of LP...
Those first machines could only play/record SP (2hr) and LP (4hr). The EP, (6hr) sometimes called SLP, speed came out after that. I do have a later machine, badged as a Panasonic, but basically the same as the RCA (which was made by Matsushita) with the added speed and dressed up case. I believe you can also preset 4 programs on that one rather than the single on the earlier machine.
Those first machines could only play/record SP (2hr) and LP (4hr). The EP, (6hr) sometimes called SLP, speed came out after that. I do have a later machine, badged as a Panasonic, but basically the same as the RCA (which was made by Matsushita) with the added speed and dressed up case. I believe you can also preset 4 programs on that one rather than the single on the earlier machine.