Red Knob Encrusting Sponge. I have to do more research what kind it is. As of right now, it is super hardy. The best description is that it looks like a couple of small ball sponges which are smaller but it is spreading like a carpet. Very nice and vivid red color. We will probably sell them in the size comparison of the diameter of a baseball. I don’t have a picture yet but it should not stop you from buying this addition to our website.