Steering knobs/ spinner knobs are driving aids for handicapped drivers. A spinner knob is a more affordable and convenient option, rather than purchasing handicap equipped cars or handicap transportation.
The knob is directly fixed to the steering wheel that can be used to hold/ grab the steering wheel.
This video is about different types of steering knobs or spinners when a person with disability drives.
Simple Spinner/ Knob
Palm Clutch Spinner
One Pin Spinner
