Just over half the diameter, yet slightly longer than 406x. Grid looks built-in, providing an additional 1dB response boost up top (+4dB verses +3dB with short grid).
Comparing 6060 to 4060 Core version-
Same 134 max SPL, 1dB(A) higher noise floor, 3dB lower 1% THD distortion point, 4dB lower dynamic range, 1dB(A) lower S/N
I expect this to be welcomed by the theater/film/TV sound market, if not really a game changer there as they already have other 3mm diameter mics, other than presumably improved sound quality in that format which I've no reason to doubt. But I don't see it as much of a game changer for us, other than being marginally more useful for super-stealth situations. This is more evolutionary than revolutionary.
I'm going with the Core version of 4060 next time, it's is small enough, performs slightly better, and is less costly. My main wish is that DPA would release a 4060 variant without the integrated cable, placing the microdot connector at the back of the capsule.