Fitbit Flex 2 Charging Cable | FB161RCC / FB161RCC-WMT | NEW Keep your Fitbit Flex 2 Activity Tracker charged so you'll never miss a step! This slim charging cable easily packs into purses, backpacks and more, and plugs into any USB port, so you always have the power you need to track your routine. Replacement Charging Cable Cradle Dock Adapter with 6.7" (170mm) Cable Length for Fitbit Flex 2 Fitness Wristband. Does ** NOT ** fit Fitbit Flex E4042