A:Answer The SanDisk Extreme 32GB microSD card fulfills all of the minimum requirements for any HERO3, HERO3+ or HERO4--even the professional-level Black Edition cameras (which tend to be the most demanding on cards).
FWIW I typically record footage in the more demanding settings (1080p120, 2.7K60 & 4K30) and this card has the ability to keep up with the camera's bit rate--no freezing, no hesitation. This is my go-to card (I now have 5), and will continue to be (I would assume) for quite some time.
NOTE: Specifically for this model of SanDisk Extreme, stay with the 32GB or 64GB capacities, as the 16GB SD card actually showed reduced write speeds in my home-grown tests.
