Does the job but ...
No ambiguity in the description, it is indeed a TOSLINK to mini TOSLINK adapter plug (3.5" optical jack used mainly on MD players, etc.).
I put a bad note because the ribs of the part do not respect that of the TOSLINK standard. The consequence: no locking of the TOSLINK plug in the adapter. It is thus necessary to make sure of the contact of the fibre with the optical conduit of the adapter and especially not to move the cable at the risk of having a sufficiently large gap to have an attenuation of light going until the loss of the S/PDIF signal...