Manual gear , turn around to change gear in a hurry.Back on the spot and stuck. You need one of these boosters to make your driving experience more comfortable. rotation, refuse to jam.Anti - silicone shell, sweat no , no odor exposure note: this product can only be used under 20km/h as an auxiliary power ball.Make the boosters are fixed driving and 't rely on too much.Everything is for your safety. Use: 1. Select the appropriate installation position on the steering wheel (generally, it is recommended to install it in the upper corner, of course, depending on personal habits). 2. First, separate the power boosters' buckles and install in the installation position, then buckle the bottom parts of the power boosters 3. Tighten the two screws with an inner hexagon wrench. 4. Confirm the fixation.Test stability at a stop 5. If the steering wheel cover is installed on the steering wheel, remove the u-shaped rubber pad installing it Knob Ball Applicable model: most models Colour:Black Material:metal Size:: 63 mm x 22 mm x 50 mm Package Contents: 1x steering wheel booster ball Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.