Period–mass density distribution of present-day WD+MS PCEBs for two of our four best models (gray scale) compared with the observational distribution (magenta and blue squares). The blue squares denote those systems for which the effective temperature of the WD is lower than 12 000 K, in which case the mass determination of the WD could be problematic. The top panels show the population of WD+MS PCEBs containing C/O or O/Ne WDs, middle panels are for systems containing a He WD, and the bottom ones show the entire population of WD+MS PCEBs simulated.