Danfoss Radiator Valves with band : where can we buy new replacements?

I have Danfoss Radiator valves on all my radiators, the one which is held on to the pin by a screwed on band.

How and where can one obtain this type of danfoss radiator valve to replace those which have broken 'teeth' and can no longer be held on by the band, no matter how one tries to do it? What is the model number of these?

Any help would be appreciated, with thanks.