I'm not sure, but is it possible that you're referring to something like a camlock with an Abloy Protect or Disklock core? (The warding on some of those systems can look like a pair of back-to-back D's?) If so, Han Fey has an
excellent set of articles that look at the entire series of Abloy systems... they might help you narrow down the specific model that you're wondering about.
...then again, if you're referring to an Abloy with some other sort of "double D", you make have just touched on some of Jaakko's secret fantasies.
