A mat seal for an electrical connector, including: a front face, a rear face opposite to the front face, and a plurality of passageways each adapted to receive a cable to be inserted through the passageway, at least one cavity in at least one of the front face and the rear face, wherein at least two first passageways of the plurality of passageways open into one of the at least one cavity, and wherein at least one second passageway of the plurality of passageways opening into the front face and the rear face of the mat seal.