Holding the right button for 3 seconds in the main timekeeping mode leads the display to show "CASIo", which is useful to spot a counterfeit model (applicable for newer models of the F-91W and its variants, including F-94W and A158W)
Holding the right button for 3 seconds in the main timekeeping mode leads the display to show "CASIo", which is useful to spot a counterfeit model (applicable for newer models of the F-91W and its variants, including F-94W and A158W)