OEM Style Gaggio Thermostat Replacement Thread M4 145°C by Sungaze Coffee - Maintain Perfect Brewing Temperature - Authentic OEM Classic Pro, Baby, Evolution, Espresso - Simple Installation | Steam

You can find them easily on Amazon for about 10 bucks. You are looking for 145C for the steam thermostat with an M4 thread. One option https://a.co/d/03ia5q9X Please install with care. Generally you can take some of the thermal paste from old one for the new. Otherwise get small tube of paste also. Paste is necessary for thermal conductivity. Do not use tools to install. Hand tightening is adequate. If you use a wrench be very gentle.