Electrical connector comprising: - a one-piece sealing mat made of a deformable material body having, in a rest condition of the mat in which no stress is applied on the mat, a thick portion and a thin portion each having: - an upper face - a lower face parallel to said upper face, - at least one hollow passageway (7, 12), in each one of the thick portion and the thin portion, extending along a longitudinal axis from said upper face to said lower face for sealant reception therein of an electrical member, the longitudinal axis of the passageway of the thick portion being parallel to that of the thin portion, the thickness of the thick portion, measured along said longitudinal axis, being greater than that of the thin portion, - a housing for reception of the electrical members for connection to a complementary connector, the housing comprising a receiving portion, - a grid comprising a compression portion facing the receiving portion of the housing, the grid being locked to the housing so that the sealing mat is compressed between the receiving and compression portions, characterized in that: the at least one hollow passageway of the thick portion is a broad passageway for receiving thick electrical connection members, and the at least one hollow passageway of the thin portion is a narrow passageway for receiving thin electrical connection members. - a one-piece sealing mat made of a deformable material body having, in a rest condition of the mat in which no stress is applied on the mat, a thick portion and a thin portion each having: - an upper face - a lower face parallel to said upper face, - at least one hollow passageway (7, 12), in each one of the thick portion and the thin portion, extending along a longitudinal axis from said upper face to said lower face for sealant reception therein of an electrical member, the longitudinal axis of the passageway of the thick portion being parallel to that of the thin portion, the thickness of the thick portion, measured along said longitudinal axis, being greater than that of the thin portion, - an upper face - a lower face parallel to said upper face, - at least one hollow passageway (7, 12), in each one of the thick portion and the thin portion, extending along a longitudinal axis from said upper face to said lower face for sealant reception therein of an electrical member, the longitudinal axis of the passageway of the thick portion being parallel to that of the thin portion, the thickness of the thick portion, measured along said longitudinal axis, being greater than that of the thin portion, - a housing for reception of the electrical members for connection to a complementary connector, the housing comprising a receiving portion, - a grid comprising a compression portion facing the receiving portion of the housing, the grid being locked to the housing so that the sealing mat is compressed between the receiving and compression portions, characterized in that: the at least one hollow passageway of the thick portion is a broad passageway for receiving thick electrical connection members, and the at least one hollow passageway of the thin portion is a narrow passageway for receiving thin electrical connection members.