Teac head set model unknown rec play erase 53786011 50664600

A set of heads , but I do not know from which machine, they have not been lapped as that would make them too expensive, though I can get them done if needed. no head gaps visible.

These were interesting as they used a 4 track head in a two track unit using just tracks 3-4, never seen that before.

May have been used in other units around this time