A mat seal for an electrical connector includes a plurality of through-holes extending in a through-hole direction through the mat seal, a grid of a first material having a plurality of grid meshes, the grid is arranged with the through-holes extending through the grid meshes, a first material layer of a second material disposed on a first side of the grid, and a second material layer of a third material disposed on a second side of the grid opposite the first side. The first material of the grid has a greater compression modulus than the second material of the first material layer and the third material of the second material layer.