This adorable shark dorsal fin is attached to an elastic band which you can put around your dog's tummy and give him that dagerouse look they've always wanted. The smaller the dog, the cuter it looks! Fits medium size dogs. The belt is elastic and then there is Velcro to clasp it at the end. There is also an extra piece that you cannot see in the photo. There is another mini belt that connects to the dogs collar that hold the fin in place. 100% polyester.