Driver airbag with extension adjacent rear panel

An assembly comprising:

• a steering wheel;
• an airbag inflatable to an inflated position and having a main chamber supported by the steering wheel;
• the main chamber in the inflated position having a rear panel facing the steering wheel, an impact panel opposite the rear panel, and an outermost periphery between the impact panel and the rear panel;
• the airbag having an extension having a first end and a terminal end and extending from the first end to the terminal end adjacent the rear panel of the main chamber between the main chamber and the steering wheel when the airbag is in the inflated position, the first end extending from the outermost periphery and the rear panel, and the terminal end being connected to the rear panel;
• the extension being between the rear panel and the steering wheel when the airbag is in the inflated position;
• and
• the airbag having an inflation chamber extending from the main chamber to the terminal end through the first end of the extension, the inflation chamber being between the steering wheel and the rear panel.