The DPA 402x mics are pre-polarized condenser capsules with a VERY conservative max SPL of 145db
Any comparison of the DPAs to the $2 Panasonic capsule probably is not very realistic.
Those DPA 402x series are some of the finest microphones made, IMHO
The DPA 406x series are electrets, but their sound is markedly better than any incarnation of the Panacapsules to my ears.
Pre-polarized condenser = electret? Of course, we cannot compare mass produced low price ones with the DPA, AKG, Earthworks etc.