A steel rectangle from the 1980s that never went out of production.

The A168 is a black LCD in a rectangular steel frame, with the function labels printed in amber around the screen. Time in large digits, day and date in small ones, a PM flag. It is the layout every digital watch since has either copied or reacted against.

Four corner buttons do everything. There is no crown, no bezel and no menu deeper than one press. The stopwatch, the daily alarm and a calendar that runs to 2099 are the whole feature list, and after four decades nobody has asked for more.

Unlike the resin F-91W, the A168WA-1 puts a stainless steel bracelet and a steel case front on the wrist, over a resin body. It weighs about 50 grams, and the bracelet is the reason this reference reads as a watch rather than a gadget.

The case is 36.3mm across, 38.6mm long and 9.6mm thick, which is small and flat by any current standard and is why it disappears under a cuff. The crystal is mineral glass, which is a step up from the acrylic on cheaper Casios.

Casio rates the A168 at 30m, or 3 ATM. That is rain, handwashing and sweat. It is not a swimming rating, and the steel bracelet does not change that. Anyone who needs to get a cheap digital wet should look at the 100m-rated AE1200 instead.

The cell is a CR2016, rated around seven years, and replacing it is a job for any watch counter. Over a decade the running cost of the A168 is one coin cell and whatever you spend on the bracelet you eventually scratch.