Hi Dirk
Do you mean the thermal circuit breakers in the switch panel? A web search for " ETA 1110-F112-P1M1-10A" , replacing the 10A with the value you want, should find a number of suppliers. They are around £20 each in the UK. I replaced a good few of them as they had gone intermittent and would occasionally shut down the electronics or turn the tricolour into a flashing distress signal. They are supposed to be self-cleaning but probably not designed for long term marine use. They were simple enough to replace using a soldering iron.
Ewan