All pinwheels come in two different sizes to fit pets both large and small. Each pinwheel has a soft Velcro attachment which allows you to quickly and easily fasten to any collar. Velcro and go! Great for everyday wear or celebrating any occasion—from holidays to birthdays, to every special milestone in between! All US resellers are compelled to follow our MAP policy: https://www.huxleyandkent.com/Map-Policy