Suicide Knob Steering Wheel Spinner. Add-A-Pic Here is a nice accessory for your favorite ride. Unscrew the cap and put in your girlfriend's picture. Better put a piece of tape over it if the wife is around! It measures about 1 5/8" wide at the top and is about 1 1/2" tall not counting the base. This knob is not as smooth as the other spinners I sell. Better save an old shoe tongue to protect the steering wheel paint. Notice that it has 2 phillips screws to tighten the straps. The listing is for the assembly as shown.