Bill Paxton wears a Seiko S234 Pulsemeter

Of all the Colonial Marines who land on LV-426 in James Cameron's Aliens (1986), the one who panics is Hudson. Bill Paxton plays him as pure bravado until the bravado runs out, and then as the man howling the line everyone quotes, game over, man, game over. It works precisely because the fear is real. Hudson is scared for most of the film, and he keeps fighting anyway.

There is a small joke on his wrist, whether or not anyone meant it.

The watch is a Seiko pulsemeter, the all-black model Seiko numbered the S234-501A. It is the same watch a number of the marines wear, the one you can spot in the mess-hall scene with Bishop and the knife trick. Seiko built it in the early 1980s for runners and gym-goers, with a resin case instead of steel, which made it lighter and harder to drown. It did something most watches of the era could not. It read your heart rate.

It did not do that from the wrist alone. The pulsemeter came with a chest strap and a touch sensor, and the watch displayed what they measured. Strap one to a person and you could watch a pulse climb in real time. Which is the joke. Of every marine who could have ended up with a heart-rate monitor, it went to the squad's most dependable panic, a man whose pulse you could read across the room without Seiko's help.

There were two versions of the watch in the film, identical but for color: one with bright yellow buttons, and the blacked-out S234-501A. The marines wear the black one. That is the right choice for a unit that tapes over anything likely to catch the light, and it is the sort of detail that rewards close attention to a movie where most of the gear was built rather than bought.