Hi Jon,
It’s most probably a 6.3 amp 250 volt ("250v" rather than "250ma") fast blow fuse, in the common 5 x 20 mm size (the smaller of the two physical sizes SR offers, the other being 6.3 x 32 mm). If the internal filament is a straight piece of wire, rather than a spiral coil or a flat conductor having substantial width, that would provide added confidence in my assumption.
Good luck. Regards,
-- Al
It’s most probably a 6.3 amp 250 volt ("250v" rather than "250ma") fast blow fuse, in the common 5 x 20 mm size (the smaller of the two physical sizes SR offers, the other being 6.3 x 32 mm). If the internal filament is a straight piece of wire, rather than a spiral coil or a flat conductor having substantial width, that would provide added confidence in my assumption.
Good luck. Regards,
-- Al