The strongest hinge on the market. Vermin door accepts both 30 and 50 Amp cord. Replaces any round hatch up to 4-1/2". Can replace 370-1-A and 370-2-A as an upgrade. Resistant to road salts and acids. Paintable. Cutout Dim: 3-1/2". Outside Dim: 5-1/8". Collar Depth: 2-3/8".