Free size fit your wrist depend on button site you place. Comfortable for sporting time,Look good no matter what you are wearing. Silicon Fastener Ring For Free - designed specially for fitbit flex to protect the clasp loose and band fall off. Personalize your wristband to match your daily style with this brand new color choices. Free size wristband accessory ,High quality and Replacement for lost or damaged Bands.7 Days Unconditional Return Period. NOTE:No Tracker or other parts! For Fitbit Flex Band only! Not for Fitbit one or other Models! Replacement Rubber Bands with Clasps Only.