I recently picked up a Casio F91W for an upcoming project, but then decided it might be worth starting with its upgraded brother, so I ordered myself an A158 to use instead. It warranted a separate review, so keep reading to learn more!
Casio A158 First Impressions
Despite its low price (still under $30), the A158 has a classy look. The fully polished metal case gives it a functional and technical appearance.
Casio A158 Details
The A258 also has a few color variations available. I chose the basic black "1CR" model (same suffix as the F91W). It does have some "pops of color" with red, blue, and gold accents on the faceplate.

The metal case is angular. The bezel says "Water Resist," although the amount of water resistance is not stated. I expect that it would be fine for light water exposure.
Wearing the Casio A158
The A158 is so thin that it almost disappears on the wrist, although it weighs more than the F91W. For an all-metal watch, it's comfortable. The appearance is also more versatile than the plastic F91W.


The buttons are easy to operate. Despite the small size, the positive LCD is also easy to read, even at angles.
Casio A158 Strap and Replacement Straps
A stainless steel bracelet is included. It's easy to adjust the size and features a stamped, flip-lock clasp.

StrapHabit TQ18 Q Timex straps also fit on it. The bracelet can be easily removed with a spring bar tool (the lugs are not drilled like on the F91W.

Casio A158 Movement (Module)
Module 593 is easy to set and adjust without instructions. The functions are described on the face plate. It features a time, day, and date display, an alarm, and a stopwatch. A dim light is also available, but it doesn't have afterglow like a G-Shock (the light only displays while the button is held).

Casio G-Shock A158 Conclusion
The A158 is the classier big brother of the F91W. I expected it to cost at least a few dollars more, but it is priced the same, at just under $30 (plus they are easy to find on sale). If you're looking for a classy metal watch with basic functionality that you don't have to worry about, definitely check out the A158.

Casio A158 Specifications:
Name: Casio A158
Reference Number: A158WA-1CR
Price: $29.95
Width: 36.8 mm
Height: 33.2mm
Thickness: 8.2mm
Lug Width: 18mm
Weight: 46g
Movement (Module): 593
Battery Life: 7 years
Water Resistance: Yes
Crystal: Resin
Bracelet: Stainless steel