Outer Header Seal, 76-91 Chevy Blazer and GMC Jimmy, Each. Replaces OEM # 15590455. Mounts on the front of the removable cab shell with weatherstrip adhesive (not included) and presses against the cab weatherstrip. This seal is for the double wall models only. Made from high quality ozone resistant EPDM rubber from the original specs for a great fit and long life.