I was always getting the E220's mixed up with the E121's. I found an old thread on Net54 where several people had even gotten cards graded by PSA that had mistaken one for the other. Here's the thread:
https://www.net54baseball.com/showthread.php?t=148662
The quickest and easiest way to tell by looking at the front of the card is that the E220's have the player name inside the frame of the picture and the E121's have the name outside of the frame.