Xiemin USB Replacement Bluetooth Wireless Sync Dongle for Fitbit Alta/Blaze/ Charge/Charge HR/Surge / Flex/Force / One Activity Monitor Trackers (Fitbit Dongle Replacement) Compatible with Fitbit OneFitbit FlexFitbit Charge FORCE, Fitbit Charge HR, Fitbit Surge, Fitbit Blaze and Fitbit Alta activity tracker. Please note that this item does NOT FIT for Fitbit ZIP model. With output short circuit, over voltage and overload filter protection prevent your device being damaged by overcurrent. Small and lightweight design more convenient to carry. Easy to use. Plug and Play. Please Notice:The best syncing distance between the Fitbit tracker and dongle is within 1 meter(3.3 feet). Package: 1pc Replacement Dongle for Fitbit Trackers.