Fitbit Flex band By Allrun, Newest Replacement Adjustable Wristbands for Fitbit Flex Only / No tracker / Wireless Activity Bracelet Sport Wristband (Black&White) Specially designed to fit the Fitbit Flex Only. Fitbit Flex device NOT included. The Fitbit Flex Color Bands feature a top window cutout that reveals the device LED lights. Extra Lightweight Extra Comfortable. Never lose your FitBit Flex. Fix the tracker fall off problem. One size fits most wrists size. Designed to fit most wrists (Band Length: 225mm / 8.86"). Less is more. Enjoy your simple life! Makes your Fitbit Flex look great.