It looks net, but I much prefer my filter socks. I know people complain about them, but I really don't understand why. I change my sock once a week, no big deal. My last tank was extremely heavy bioload and had to be switched twice a week. Easy enough, takes less than a minute. I also find that when I have tried to put media such as ROWAphos in a mesh bag in the sock, it gets trashed in there, no good. Seems like added work to use the cup over a sock to me.