I suspect the B3's are probably even more water resistant than the DPA 406x just because the diaphragm under the grid is a flat stainless steel metal surface and less likely to retain water and go mute than the DPA capsule. Both have an atmospheric vent somewhere on the body, so don't submerge them deeply else water pressure could force water inside which would likely kill the mic. But wouldn't worry about rain, splashing, or submersion and swizzling in a glass of water, condom or whatever.