When working with 4K resolution cameras, it is important to make sure your SD card can keep up. We use a couple of the SanDisk 64GB Extreme Pro cards to capture and transfer our media. Designed for Raw, JPGS, and video, this card can write at a speed of 90 MB/s. Because we are located in Upstate New York, the weather can be unpredictable. These cards are tested under harsh conditions such as water, shock, x-ray, and cold weather, which is exactly what we need for the environments we shoot in. 

B&H Link: http://www.bhphotovideo.com/c/search?N=10824149&InitialSearch=yes&sts=pi