I bought two of these for my two dogs. Very thick and warm for real cold days. Styled like a fisherman's sweater which is a thick knit. My dogs wear their sweater under a thin nylon coat because they run through bushes off-leash and the coat keeps the sweater from being snagged. This sweater is thick and makes the outer shell snug so I probably should have bought a different style from the same manufacturer. So if this is a layer under a harness or other protective item, consider if the outer layer will still fit or if you'd be better off with a different wool style. The wool is a much better option than nylon/poly sweaters available in pet stores - warmer and breathes. Handmade and sizing is inconsistent as my two sweaters in the same size were very different in actual size. Unless your dog is elderly or ill, this is definitely an outdoor cold-weather sweater (it was 19 and snowing when my dogs walked in their sweaters this morning). I would not suggest using it in a heated house or you could over-heat most dogs. Excellent product and unusual to find a dog sweater in a 100% wool fabric.