The Vacuum Power Brake Booster 54-74111 by Prior is designed to fit 1983-1988 Ford Thunderbird and Mercury vehicles. Made of steel with a housing diameter of 9.555 inches and a diaphragm diameter of 9.26 inches, this brake booster comes with a booster unit and instruction sheet included. It has a manufacturer warranty of 5 years and a stud thread size of 3/8x16. This product is a genuine part with the OE/OEM part number E3SZ2005A, making it a reliable choice for maintaining the braking system of your classic Ford or Mercury vehicle.