Compatible Model: Compatible with Fitbit Inspire & for Inspire HR Fitness Tracker & Ace 2 only. Coming with 2 pack replacement USB charging cable. NOTE: Please connect it to the USB port on the computer for charging. If you connect it to the adapter, the current must not exceed 1A and the Voltage does not exceed 5V.( NOT WORK FOR FITBIT INSPIRE 2)^ Safe and Fast Charging: Adopting high-quality materials and high-end manufacturing process, make your watch charging faster and stable. Built-in short-circuit and overload protection, provide stable and safe charging for you. PTC(internal power protection) keeps your for Fitbit Inspire HR safe.^ Plug & Play: The charger cord charger design with USB port. You can charge your for Fitbit Inspire & for Inspire HR by plug your laptop, PC, Mac, Notebook USB port or 5V/1A adapter. Charge cable is easy to carry on and making it convenient for you to charge your watch.^ Simply & Portable: 3.3ft long charging cable provides you convenient use and the flexibility you need. With this special designed charging dock, you dont have to remove your watch band while charging.^ Tips: Make sure that there's no fan or vibration on the same surface as the device when you charging. If so, we suggest that you place the tracker on a different surface without any vibrations, avoid the cable too short and easy to loosen, leading to charging failure and see if the issue persists.