The CZ-40B was a joint marketing effort between CZ and Colt. Colt was trying to reenter the US "police" market and sought to develop a gun suitable for that audience.
(Read: DAO only, no safeties, etc., double-stack mag to allow special LEO hi-caps, 1911 grip angle [?!], and moderate size.)
The CZ-40B is pure CZ-75B with a 1911 grip angle. The grip is much wider than a 1911, so only the angle is the same. But some really like the angle. The Colt was to be double-action only, and a few people who have posted here claim the Colt Z-40's double-action only trigger was superb.
There was much said about Colt's engineering input, but it was apparently "limited" or "none." Standard mags fit the gun, and all internals are virtually identical to the 75B line. The slide is INSIDE the frame as with all other CZs, and the slides will even inter-change with the 75B line (but they won't function properly -- close, though.)
(The Colt Z-40s aren't being shot much, as they move directly to "collector" status -- less than a 1000 were made.)
The 40B is one of the best buys around.