Amazingly, I found this one still for sale new and grabbed it up:
It's chief function, dialing touch-tone phones by emitting the appropriate tones, was never all that functional or useful, only seeming to work on some occasions with particularly well behaved phones. Still, I can't help but find the idea way cool for some reason and have been through a few over the years. The (internal, I guess) model number is 555 but it's also advertised as the DBA-80. There was also a DBA-800 in metal finish with a stainless steel band, along with slightly later models DBA-100 and DBA-900 maybe with more memory. These all came out in the late 80's but I guess have found something of a following since they can still occasionally be found on Ebay and new in shop if you're really lucky.
I'm still waiting for Casio to come out with a practical cellphone wristwatch (maybe they did and I missed it). That would be the ultimate. :bounce: