LifeRock Shroom offers infinite possibilities for personalizing any marine aquarium! Its impressive mushroom-shaped rock adds dynamic flair to reef or fish-only tanks. Each one features accurate measurements of 10" x 10" x 10" and weighs 10-12 lbs (note: variations may occur as these are handmade). Featuring real aragonitic base rock, not cement, and no curing required, LifeRock's robust macro & micro-porosity boosts its biological performance. Plus, it's totally safe for all fish & invertebrates & incredibly unique—a responsible choice for your tank!