$ fdisk -l

[...]
Disk /dev/sdb: 50 GiB, 53687091200 bytes, 104857600 sectors
Disk model: QEMU HARDDISK   
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
[...]