They are Klixon breakers, available from Aircraft Spruce, an aircraft parts supplier. They’re not cheap, but here they are. I’ve also gotten them from Peerless Electronics.
https://m.aircraftspruce.com/catalog/elpages/klixon7277.php?gclid=EAIaIQobChMIitPVhbb93wIViorICh0fXQBIEAQYAiABEgIy2vD_BwE
I’ve used the 7277-2-# series, where that last number is the ampacity.