On the modular flue gas probe with a 335mm long probe shaft, the flue gas path, and temperature channel can be conveniently connected to the measuring instrument via a practical bayonet lock. The probe shaft is also easy to replace, thanks to the quick-change click system on the handle. The thermocouple NiCr-Ni, which is integrated with the probe shaft, enables temperature measurement up to 500°C. The probe is also supplied with a cone for attachment.