Is this card fast enough for 4K video?

Yes. The U3 and V30 ratings guarantee a minimum sustained write speed of 30MB/s, which covers standard 4K recording on action cameras and drones. Very high-bitrate modes such as 4K at 120fps may need a faster card.

What does the A2 rating mean?

A2 is an application performance class. It means the card is rated for a minimum number of random read and write operations per second, so apps and games stored on it launch and load faster than on a plain card.

Does it work in a DSLR or laptop?

Yes, with the included SD adapter. The card itself is microSD, so the adapter lets you use it in full-size SD slots on cameras, laptops and card readers.

How does it compare with the Canvas Go Plus in other capacities?

It is the same SDCG4 line. Read speed of up to 200MB/s and the U3, V30 and A2 ratings carry across the range, so pick the capacity that fits your recording time and app library.