This is our Medium size Acropora Gemmifera measuring 7x 6.5 x4.5 inches. These are made of a durable, flexible and nearly unbreakable UV stable polyurethane composite safe for all aquariums. Many colors to choose from. Thank You and enjoy the finest artificial corals! Call or email us anytime with any questions at 1-888-637-6598 or oceanaquaria@gmail.com