mount for a programmable heater-thermostat

I just bought a cheap programmable heater-thermostat but unfortunately there was no fitting adapter for my heater inside the box.

Heater diameter Ø 30 mm (seems to be no common inch-thread)

To mount the programmable thermostat you have to cut and remove the union nut of the programmable thermostat.

Will be tighten by using two M3x10 (or longer) hex socket screws and two M3 nuts.