Fit our 4.5 pound long-haired chihuahua perfectly (see photo). It goes over her harness. This morning's walk was in high winds and 20 degrees. It seemed to keep her warm, though it was a shorter walk than usual, mainly for my benefit! I wish the slit on the back for the harness were just a little bit longer since for our particular harness it takes some fussing to access the loops for putting on the leash.UPDATE: Over three years later and this little coat is going strong. I purchased a simple snap button kit and replaced the Velcro with snaps (see photos). This was preventative, as the Velcro will weaken over time. Plus, it makes it a bit more secure and simple, and I don't have to worry about constantly picking dog hair out of the Velcro loops. I've probably gone on about 150 walks total using this product.