driver is wearing a long-sleeved shirt, the protruding accessory on the rim of the steering wheel can also become caught in the sleeve's open cut by the button. Attempting to free a tangled shirt sleeve from the knob may cause the driver to lose control of the car. Other names include "granny knob", "necker's knob" because it facilitated driving by using only one arm leaving the other arm for romantic purposes, and "wheel spinner." Legality Brodie's knobs are legal on private vehicles in most U.S. states. U.S. Occupational Safety and Health Administration regulations restrict the use of auxiliary devices for specific construction vehicles. OSHA prohibits modification of industrial equipment without the approval of the equipment manufacturer. References Automotive accessories Control devices Vehicle parts Tractors