RM Sotheby’s has announced it will sell the three iconic Alfa Romeo Berlina Aerodinamica Tecnica Concepts that were introduced at the 1953, 1954 and 1955 editions of the Turin Auto Show.

The concepts, known as the B.A.T. 5, B.A.T. 7 and B.A.T. 9d, were designed by Franco Scaglione and handbuilt by Bertone. They are considered among the most important automotive concepts ever built and will be sold together at the company’s Contemporary Art Evening Auction on October 28.

Read Also: BAT80 Batmobile Is A Spectacular 80th Anniversary Present For The Dark Knight

The first of them was the B.A.T. 5. Scaglione designed a concept that would maximize airflow, which gave it a unique aerodynamic shape unlike any other vehicle of the time. It is finished in a dark shade of grey and made its public debut in May 1953 at the Turin Auto Show. In October of the same year, it was sold to American importer Stanley Arnolt and displayed in the U.S. Arnolt drove the car for a few years before selling it to Joe Pyrsak, who kept it for 30 years.

B.A.T. 5

In 1987, B.A.T. 5 was sold to a collector in California and underwent a year-long restoration before being displayed at the Pebble Beach Concours d’Elegance in August 1988, where it won a class award.

Like the B.A.T. 5, 1954’s B.A.T. 7 used the running gear of an Alfa Romeo 1900. Scaglione narrowed the front air intakes, lowered the body by over two inches and lengthened the iconic tailfins. The concept has an incredibly low drag coefficient of just 0.19, lower than any current production car. After the vehicle’s Turin Auto Show premiere, it was acquired by Alfa Romeo in 1955 and shipped to the U.S. and displayed at the New York and Chicago Auto Shows.

B.A.T. 7

B.A.T. 7 passed through the hands of various owners over the years and at one stage, the rear fins were removed as they obstructed rear visibility. However, it was restored in the 1980s and the fins were reinstalled.

Last, but not least, is the B.A.T. 9d, showcased during the Turin Auto Show in 1955. Alfa Romeo wanted this latest concept car to be more practical for road use, so Scaglione reduced the size of the rear fins and installed an identifiable Alfa Romeo front grille.

B.A.T. 9

The cars are expected to fetch between $14 million and $20 million when they cross the auction block, according to RM Sotheby’s pre-auction estimates.