My book 2.5" 4TB

I bought a My book 2.5" 4TB external drive for PC. It has the size and heavy as My book 3.5" 5TB.
Did I get a wrong products? I have a 1TB 2.5" and 100GB 2.5", they are very small and light. Is there some mistake?
Please advice!

Not sure what your question is.

My Books are 3.5" drives.

Passports are 2.5" drives.

I am confused too. That is why I asked. Please look at page:

or search model# WDBBGB0040HBK-NESN which I had mentioned before.
Hope you more clear what my question is?

Best Buy’s specifications page is wrong.