From Manufacturer
This B&H Kit features the Silicon Power 256GB Cinema PRO CFX 310 cFAST 2.0 Memory Card and a Silicon Power 256GB Superior UHS-I microSDXC Memory Card with SD Adapter. Both cards can capture and store 4K and Full HD video. Thanks to its fast read and write speeds, you'll be able to quickly offload large files for storage or editing.
The 256GB Cinema PRO CFX 310 cFAST 2.0 Memory Card from Silicon Power features a storage capacity of 256GB, uses MLC NAND flash memory, and takes advantage of the SATA III bus to support maximum sequential read speeds of 530 MB/s and maximum sequential write speeds of 330 MB/s. All of this allows for users to capture 4K video and Full HD video as well as raw still images and rapid-fire bursts. Thanks to its fast read and write speeds, users will also be able to quickly offload large files for storage or editing. Built for extreme conditions, the Cinema PRO CFX 310 is protected against vibrations of 15 g at 10-2000 Hz, shocks of 1500 g at 0.5 ms, drops of up to 2.46', and temperatures ranging from 32 to 158°F.
Please note that this card supports the CFast Type I form factor. CFast cards with a Type I form factor can be used in devices with CFast Type I and CFast Type II slots.
The 256GB Superior UHS-I microSDXC Memory from Silicon Power keeps up with the pace of your life, allowing you to capture Ultra HD 4K and Full HD video, as well as raw and JPEG stills and bursts. Built with a storage capacity of up to 256GB, this card features a maximum read speed of 100 MB/s, a maximum write speed of 80 MB/s, and a thanks to its V30 / U3 rating, write speeds are guaranteed not to drop below 30 MB/s. If your device does not support V30 / U3, there is backward compatibility for Class 10 / U1 devices.
Aside from support for UHS-I, V30, and U3, Silicon Power built this card with support for the Application Performance Class 2 (A2) spec, which includes optimizations to give Android users an improved mobile experience, delivering faster mobile app performance. The A2 spec allows the card to manage random read input-output access per second (IOPS) operations so it can quickly open apps and process accompanying tasks, such as audio, graphics, saved profiles, and in-app permissions.
Designed and tested to withstand harsh environments, Silicon Power's 256GB Superior card is resistant against water, shock, and x-rays, as well as temperature extremes of 32 to 158°F. It can also endure a minimum of 10,000 insertions. So that this card may be used in SD-compatible devices, a microSD to SD adapter is included.