Oceans Wonders Ceramic Coral Frag Plugs are perfect for the propagation or fragging of hard and soft branching corals such as Acropora, Birdsnest, Montipora, Kenya Trees, Xenia, ect. They are 1-1/4" in diameter and 5/16" thick. Ceramic frag mounts are fired at nearly 2000 degrees in a high temperature kiln making them 100% inert and safe. They never have to be cured and are shipped dry, ready to use.