Business Card Holder 3-Book Set (KOKUYO, KING JIM)

This is a set of 3 business card holders.
It can hold a total of 1400 cards.

① KOKUYO
Holds 300 cards

② KING JIM
Holds 500 cards

③ KOKUYO
Holds 600 cards

There is no writing or marks on them. I believe they are sufficient for managing business cards.
Thank you.