We bought this for our standard poodle in a size large, it fit true to size with the measurements we took. The waist band has a bit of elastic in it and with the wide velcro straps and the soft fabric we believe this fit her comfortably! The hole for the tail seemed small at first, but fit well with plenty of room for her to wag and move as she normally does. We bought this particular diaper because she was in heat and those disposable ones were really bothersome (she was always biting through them and tearing them to shreds). The design is pretty and feminine and she was so much happier with the cloth diaper (lined with two pantyliners in the shape of a T for easy hygiene). We received the item in a timely fashion, despite living in Alaska where we oftentimes see delays in shipping, and it came as described. Great product! Great seller!