so i went to petsmart looking for a sponge to cover my filter intake because a few of my ghost shrimp have been carrying around eggs. i was expecting to search forever and have to cut to fit, etc. i saw this sticker "NEW ITEM!" from fluval. i thought it was perfect, and i've never heard anyone mention using it. so i picked it up for $2.50 (+ a 1$ donation as always ) voila! it fit perfect over my filter intake and didn't affect the flow. it's also kind of stretchy so i think it would fit a variety of over the edge/in tank filters. sorry if this is old news, but new to me!