Water level indicator
A device that allows you to estimate the amount of water in the kettle without opening its lid. Most often
the water level indicator has the form of a scale applied either to the transparent wall of the container, or to a transparent insert in an opaque wall. In any case, this function allows you to measure the volume of filled water quite accurately, and not just determine it “by eye”. This possibility is especially important for models with open coils (see "Heating element"), in such devices, a mark on the indicator is usually applied to the minimum allowable water level.
Thermometer
A device that displays the temperature of the water in the kettle. The presence of a
thermometer is useful if the water needs to be heated to a certain temperature. However, the thermometer does not automatically turn off the kettle, unlike a thermostat — this must be done manually. Also, the thermometer allows you to assess how much the heated water has cooled over time and whether it can be used without heating again.
Removable lid
The ability to completely remove the lid of the kettle. Such a possibility is not of particular importance during regular use, however, it provides additional convenience if the kettle needs to be washed from the inside — a
removable lid, unlike a traditional non-removable one, will not hang on the fixture, hit your hands and create other discomforts. On the other hand, there is a certain risk of losing this lid, so this feature is not common.
