Please check dimensions before purchasing. Our high-quality nature design aquarium decoration is made of brown clay fired at high temperature. This makes the pleco cave absolutely safe for people, aquarium fish, and pets. The decoration can be used for reproduction of many kinds of plecos such as Ancistrus (Bristlenose pleco), Hypancistrus, and Peckoltia. The dimensions are selected based on our 10 years of experience in breeding plecos. Just flush the tube in running water before use. We pay great attention to the design. Our products have the texture of natural materials such as tree logs. This allows our pleco cave to fit organically into any aquarium and serve as decoration. It also can be used in aquascape design for a natural aquarium. What's more, pleco caves can be used as shelters for various cichlids and shrimps.