With Windows 10 Home in the file manager, 256,020,316,160 (256 GB) are displayed. The stick is formatted with exFAT.
In other words, the stick has the full declared capacity.
I have tried other USB sticks in this price and specs range. But the Extreme Pro is much faster! I can't explain why this is the case, but my feeling is that it is at least 5 times faster than the others.
Both when writing from Rekordbox and when reading (I use .wav files) on the player (play mostly on 2000 Nexus), this stick is the non plus ultra for me!!! I usually recommend the stick to other DJs - I am completely convinced of it.
The stick should have the FAT32 format. As far as I know, Windows 10 is not able to format to FAT32 without external tools. But there are free portable programmes that can do this.
As we are in a living market, price fluctuations are nothing special. Moreover, we work with daily prices, so the price of an offer can change at any time.
Your phone has a Type C connection, the stick has a Type A connection: you need an adapter accordingly,
Alternatively, a USB memory device with an additional Type-C port: https://www.digitec.ch/de/Comparison/6012293-6146667
You may still have to format the stick.
You may also need to clarify with the phone whether the 256 GB is compatible.