I love it! Works great in my Galaxy Note 8! Fast enough that I can throw pretty much anything at it. If you're wondering, modern Android versions (starting with Lollipop, as I recall) have the ability to read up to 1 TB of external storage. While this 400GB card is the maximum capacity you can currently buy*, the leading manufacturers are feverishly working to make larger capacity cards. For now, though, I think 400GB is enough to handle all the 4K video I can shoot.
*- Don't be fooled by unscrupulous sellers, particularly on auction sites ( I won't name it because there are a lot of fake cards here, too), who list ridiculously large capacity cards for astonishingly low prices... you don't get what you pay for! They take cheap, generic cards, usually no more than 4 or 8 GB, and rewrite the card's firmware & re-label it to make it act and appear like a larger card... 256GB, 500GB or higher! There are tons of listings out there for 1 TERABYTE microSD cards! Of course there's no such thing: and when the physical memory of the card is reached, your device will simply start overwriting data... and your precious photos, videos and other files will be gone forever. In fact, one third of all SanDisk cards on the market are counterfeit! You can avoid all this by installing and using a free app called SD Insight to determine if your card is legitimate.