Tascam M-520 single knobs TEAC B-15D

These are from the Tascam M-520 they look like other knobs of this period but they are for D shafts if you look underneath the moulding is marked  TEAC B-15D

16.2mm high

I am not sure if they were used elsewhere

Some colours are crazy rare so if cost is an issue go for the cheaper ones