FUNKtional Wearables Fitbit Bracelet for Fitbit Flex Fitness Activity Trackers - The Kate Single-Strap Brushed Metal and Premium Vegan or Genuine Leather Buckle Fitbit Bracelet S/M - Inner Circumference = 5.5"- 6.25" inches, Width = .6" inches *approximately M/L - Inner Circumference = 6.25"- 7.9" inches, Width = .6" inches *approximately Sizes Similar to traditional Fitbit Flex Silicon Wristband Sizing. No one will ever know you're wearing a Fitbit! Never lose your Fitbit Flex again - Super secure! This product is not an official product of Fitbit Inc. Activity Tracker not included. Color may vary slightly from photo.