A three piece bag construction for an air bag cushion adapted to be deployed in the event of a collision has reduced stress at corners of the mouth. An elongated central main panel 10 totally surrounds the two side panels 12 and 14 and has end portions which form a transition section leading from the mouth 16 to the interior of the cushion. No part of the side panels 12 or 14 extends to the mouth 16. Seams extending from the four corners of the bag mouth 16 through the mouth/attach area to the side panels 52 and 54 found in traditional bags where high stress occurs, are not used in the present invention. A novel rod and rod pocket assembly facilitates attachment of the cushion to a conventional module.