I have a GoPro 3 camera with which the cards (64Gb and 32Gb editions) work perfect.Formatting went perfect, movie recording and picture taking without any problem for the last 6 months now.However, I tried to use it in a Contour+ and the Contour GPS and both cameras are unable to use the cards, I presume these cards do not fit the Contour specifications (unable to format, no way to record on the card).So make sure the card is compatible for its intended use.