Velcro wrap straps allow you to position the bow tie as you wish on the collar or harness. Take it off and add it back for an easy on/off transition. Available in multiple sizes. Regular size measures approximately 5 inches x 4 inches - and small are 3.75 x 2.5 inches but can easily be made to accommodate different sizes. If you're unsure, simply note your dog's breed in the comment section.