These steering wheel adaptors are made to adapt the 3-bolt patterns of a steering wheel to the tapered, splined top shaft of a steering column. All IDIDIT adaptors will fit most IDIDIT columns as well as most 1969 or newer GM passenger car columns and are secured in place with a single nut. A horn wire is included. Grant and Wheel Shoppe are the most popular applications for this adaptor. Add the convenience of a horn button to your 3-bolt wheel with the IDIDI "Bell" style 3-bolt adaptor. Standard size is 1.25" deep.