A:AnswerThese are not compatible with a Fitbit. The headphones are meant to be connected with a Bluetooth sending device like a cell phone, iPod, a table with music on it.
A:AnswerThey shouldn't. I chrage them with the buds in the charging case all the time i dont know of any other way to charge them. And will charge just like your phone with a battery pack
A:AnswerYes play, pause, skip ahead, skip back and of course volume increase and decrease. I like the ease of use when it comes to using the controls on these JVC earbuds. Good luck, you'll be happy you bought them!
A:AnswerI'd approximate about 30-50ft depending on what is between you and the phone. I've gone probably 75'+ in the open but have adversely lost connection at less than 25ft inside a sheet metal building
A:AnswerThe headphones are compatible with iPhone devices. Bluetooth is reverse compatible with older and newer devices so they will work with your iPhone 4.