We used the Breath-Easy (BEM-1) with a plate lid because we were afraid of contamination. When we came on the next day it was a big mess of media leaking out, air bubbles and definitely cross contamination between the wells. We were wondering if the Breath-easy was meant to be used without a lid. We don't want to bring contamination to our incubator. That's why we are hesitant to try it. Anyone with such experience is welcome to comment.