Tommy Hilfiger rubber boots

Tommy Hilfiger rubber rain/snow boots. Black with two gold adjustable straps on each boot. These boots are in good shape but they have dusty white splotches on them. I’m not sure if it’s from salt in the snow or what caused that. (Shown in last few pictures. I would still wear them since a lot of rubber boots have the dusty look and it’s really not very noticeable, but after wearing them a few times I realize they are too tight. Size 9.