control knob
{'<entity_0>': 'potentiometer', '<entity_1>': 'control knob', '<entity_2>': 'control', '<entity_3>': 'dial', '<entity_4>': 'knob'}
[['control knob', 'use', 'control'], ['control knob', 'has part', 'potentiometer'], ['control knob', 'alternative', 'dial'], ['control knob', 'alternative', 'knob']]
A <entity_1> is a rotary <entity_2> used to provide input to a device when grasped by an operator and turned, so that the degree of rotation corresponds to the desired input. Common <entity_2> components used include <entity_0>, variable capacitors, and rotary switches. The use of a pointer on the <entity_4> in conjunction with a scale assists in producing repeatable settings; in other cases there may be a <entity_3> or other indicator which is either mechanically linked the <entity_4>'s rotation (as in many older radio tuners) or which reports the behavior being controlled.
['machine element', 'user interface']