Black Dragon Qinglong Seiryu Aquarium Natural Aquascaping Landscape Rock Decor 11lb (5 Kilo), Black Dragon Stone makes for a very attractive finish to your aquarium. Each piece is different as is a natural product and 5 kilo or 11lb in weight is usually 4 to 6 pieces. Due to being a natural product may not look like picture. Excellent for Aquascaping aquariums, terrariums, vivarium’s and other pet enclosures. These stones naturally hold heat for reptiles or other heat loving pets. They can be glued together with aquarium safe glue to create caves, cliffs and mountain ranges for fish and plants. Will not alter water chemistry and safe for aquariums. Rinse in water prior to placement in tanks.