The CaribSea LifeRock Reef Forest Extension Kit offers reef aquarium enthusiasts a versatile and eco-friendly way to expand their aquascape. This kit includes three arches, three spacers, and three rods that can be easily assembled to create intricate and three-dimensional structures within the tank. Each piece is pre-drilled with frag holes for easy coral placement without the need for adhesives or cements. The LifeRock used in this extension kit is made from aragonitic base rock instead of cement, providing a safe habitat for marine life while promoting beneficial bacterial growth through its unique porous structure.