Potentiometers are very useful in changing the electrical parameters of a system. It is a single turn 20k Potentiometer with a rotating knob. These potentiometers are also commonly called as a rotary potentiometer or just POT in short. These three-terminal devices can be used to vary the resistance between 0 to 20k ohms by simply rotating the knob. A potentiometer knob can also be used along with this POT for aesthetic purposes.