After heating source was changed to a new heatpump there was no need for a radiator thermostat anymore. This valve cap can be used on standard M30-1.5 thread (e.g. tado thermostat).
Print in PETG as PLA would soften on the radiator. Provided profile is using 270°C 2nd layer and up to cope with PETG problems (crumbling) I am facing.