43025-0400 Micro-Fit 3.0 Female Connector Housing, 3mm Pitch, 4 Way.The 4305 and 43020 series from Molex features 3.0 mm pitch connector housings, they form part of the unique, compact Micro- Fit connector system. A typical application for a connector housing is to provide a receptacle for connectors when they are mounted to a printed circuit board. These types of fittings are an essential component that offer protection for the connector and connection it is housing.