I have several from the size of an egg to as large as a man's spread hand. They are attached to live rock. Must have experience in safely removing them, also green mushrooms on sandy floor, free to school classes with salt water aquarium. Interested in sand sifting sea star, live sand, and or large wet or dry rock. Also have a green grass like coral for trade for dry or live rock of equal size. (210)240-5008. trainmaster73@satx.rr.com Have a safe day