Side zipper. I bought these for my mother, and she only wore them once to a nearby convenience store to try them out. The size seems to be the same as her usual size. She usually wears shoes that she can put on while standing, so she doesn't like bending over. The inside is fully lined with boa fleece, and the warm, subdued color and simple design mean they can be worn by people of all ages. If the size fits, please consider purchasing them. I have disposed of the box, so they will be shipped in simple packaging via express delivery. Please understand that these are used items before purchasing.