Yes it is 16 GB
Hard drives are measured using 1 GB = 1 billion bytes. Memory is measured using 1 GB = 2 to the power 30 bytes = 1073741824 bytes (also called 1 GiB). So 1 GB of RAM is about 7% more than 1 GB of disk.
This USB drive contains 14.9 GB of memory, which is 16 GB of disk. This is the normal way disk drives are specified.