X-Small: fits wrists 5-5.4 inches around and is 4.5 inches long
Small: fits wrists 5.5 inches - 6 inches around and is 5 inches long
Medium: fits wrists 6.1 inches - 6.6 inches around and is 5.5 inches long
Large: fits wrists 6.7-7.2 inches around and is 6 inches long
Extra Large: fits wrists 7.3-7.8 inches around and is 6.5 inches long
This watch band is only compatible for an Apple Watch.