1969-73 Mustang Power Brake Booster To Firewall Seal. With Bendix Style Boosters. Seal goes between the brake booster and the firewall to keep water and dirt from getting inside the car. This seal fits Bendix style boosters that are constructed with two halves that are crimped together.This seal will NOT fit a Midland booster that has a clamp around the middle holding the two halves together.Quality reproduction made of dense foam.