An ACDelco GM Original Equipment Ignition Lock Cylinder is a GM-recommended replacement for your vehicle's original component. The ignition lock cylinder is where you insert and turn the key to start the vehicle. When the correct key is inserted, the cylinder is unlocked and can be rotated. The ignition lock cylinder is connected to the ignition switch, and it also engages and disengages the steering column lock. This original equipment ignition lock cylinder has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors.