Factual error: In the scene where Lee Marvin states that Burt Lancaster loves explosions, Burt Lancaster makes a remark about the big bang theory. He says: the whole universe started with a big explosion. The film is set in 1917 which is 10 years before Georges Lemaître launched the big bang theory.
Factual error: Burt Lancaster has a roll of electrical tape on his belt when he is setting the dynamite trap, which wasn't invented until 1946.
Answer: For each member of the Professionals.