Yes Ron, I have one of those also, the alarm consists of a small rotating "hammer" based on an eccentric cam, that hits off the caseback (I kid you not).
Very effective, lasts around 40 seconds, if you're wearing it you get some vibration as well as the sound. If they're on US fleabya for $20 or so, then that's good, there's higher prices here this side of the pond, maybe more demand?

e~gards
Mel
Frae Edinburgh, Bonnie Scotland
http://www.timekeepers.me.uk
Affordable and Everyday Watches
http://www.sequencedance-online.co.uk
My other hobby - Sequence Dancing