I-SMILE 2018 Newest Replacement Wristband with Secure Clasps for Fitbit Flex Only (No tracker, Replacement Bands Only) Replacement wristband with secure watchband-style closure to keep your Fitbit on your wrist. The Fitbit accessory is a one size fits most wrists, Designed to fit most wrists (size: 6.5inch - 9.2inch). The Fitbit accessory band is specifically designed for the Fitbit Flex. No Tracker or other parts! For Fitbit Flex Band only! Free size wristband accessory. Replacement for lost or damaged Bands. Comfortable for sporting time, Look good no matter what you are wearing.