The G757-5040 was one of a string of Seikos with the same module, with variations in subtle colours of the LCD or crystal graphics, and case size/shape. The 5040 was one of two SPORTS 100 models — the other being the feted G757-5020 which was made famous on the wrist of Roger Moore in Octopussy.
This one was about as black and white as they come. While some had highlights of blue or red in the graphics, the 5040 had a thin white border on the crystal but other than that was monochrome. Bulky, since it was basically the 5020 without the horseshoe bezel, it has buttons that really need to be pressed quite hard and a solid-looking case. The two waves on the caseback indicate it’s water resistant to 15 or 20 bars of pressure.
Despite its toughness, the 5040 is no less susceptible to failing mysteriously and permanently, like all versions of this module.
Like all the G757 series, if you find one, and it’s working, wear it as often as you can. One day it will have died without notice and will most likely be impossible to resurrect.