I didn't find anything at Galaxus. But on lampenwelt.ch. Search for Danfoss adapter. The set contains all adapters.

I don't know if spare parts are available anywhere, but I have hardly needed any adapters or accessories to assemble my nearly 20 thermostats. If you like, I can send you everything I don't need against payment of postage. Otherwise I would have disposed of it. My mail address:
thf@boehi-treuhand.ch