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 for your Borgeson or Pete and Jake's wheel with the ididit "Bell" style 3-bolt adaptor. Standard size is 1.25" deep.