Mark Ruffalo wears an unidentified watch

In Avengers: Endgame (2019), Bruce Banner stands in a glass-walled room at the Avengers compound with his arms folded, reading glasses hooked into the front of his shirt, while a translucent screen behind him shows Scott Lang's face above the word MISSING in red. Between the crossed arms, on his left wrist, sits a round watch on a dark strap. The frame holds it in plain view and gives away almost nothing: a dark, mottled dial, no legible markers, no readable name.

Nobody has ever put a name on it. The communities that identify screen-worn watches have logged this one as a dark grey or titanium case, a black dial with white hands, and what might be a line of text at the bottom of the dial, and left it at that: unidentified. A watch retailer's blog that went looking for the watches of the Marvel films admitted it could not even find a usable image of Banner wearing one.

The strange thing is that the question of what Banner would wear had already been answered, in public, by the man who plays him. In June 2018, ten months before the film opened, Mark Ruffalo sat for an interview as a partner of Frederique Constant, the Swiss brand that had just launched its Hybrid Manufacture, a 42 millimeter watch with a genuine mechanical movement and a digital module that reports the calibre's own health, its rate, its amplitude, its beat error, to a phone app. Asked whether his character would wear it, Ruffalo did not hedge. Are you kidding me, he answered. Bruce Banner would love this. This is the Banner watch. It is technology; it is also just pure force.