If you want to relieve pain in arms, shoulders, back, or prevent pain from prolonged driving, this steering wheel knob can help you do it all. When you need to turn the steering wheel knob, it provides you with auxiliary force, so that you can complete the steering, turn around, parking and other actions easier. It is made of silicone and High-grade ABS with anti-slip function, and you will feel comfortable and safe when you drive with it. Especially suitable for ladies drivers, long-time drivers, Taxi drivers. Universal For Cars, Trucks, Boat, Tractors, both with and without steering wheel covers are suitable. 3.5"