The 'beep' is the dead give-away on non-Casio Casios. I have a handful of replica G-Shocks, Frogman, Gravitymaster, etc. and the beep frequency is wrong even wh

The 'beep' is the dead give-away on non-Casio Casios. I have a handful of replica G-Shocks, Frogman, Gravitymaster, etc. and the beep frequency is wrong even when the more advanced features like compass and thermometer work. For what its worth, they cost about 1/10th their genuine counterparts and are visibly identical. One last word of caution, even the F91W fakes do the three-button CASIo module thing now.