What does Diamond-x4 CZ mean?

My Husband just recently ordered me a beautiful (although fake) royal heirloom ring off the internet that came with a certificate of authenticity. On the certificate it states center stone is surrounded by 14 flawless Diamond-x4 hand cut CZ totaling 1.26 TW carats. (I already know that CZ is for cubic zirconium.) I was wondering what does the Diamond-x4 mean?