Sizing is misleading, and returns are very difficult from Europe. I carefully measured my dog, but the boots didn’t fit properly. Returning them required shipping to the U.S., which would cost more than the product, so I accepted a 30-day store credit. I then ordered a collar (size C), which also turned out far too large. Note: this model has no real adjustability—if it’s not a perfect fit, it simply won’t work. Overall, frustrating experience.