Most likely fast-recovery dual diodes. The '2001' might mean
200V and 1A ratings, but that's only a guess. Can you
make out any manufacturer markings other
than that number?

Also, what is the connection? This is probably for an output that is
clearly specified in current rating and output voltage on the
power-supply nameplate.

It might be necessary to use an uninsulated replacement part, with
insulation parts added.