Why the actual capacity less than advertised?
Computers use base 2, binary, so a kilobyte is 1024 bytes, a megabyte is 1024 kilobytes, a gigabyte is 1024 megabytes, and so on. Manufacturers work on base 10 so multiples of 1000 which is how the shortchanging occurs they advertise as a multiple of 1000 but the computer works in multiples of 1024.
So the actual capacity shown in the computer will be less than the capacity advertised.
How to engrave my logo?
Please tell us firstly before order, but the minimum quantity is 200PCS
