Crafted from natural ceramic and non-toxic. Ceramic are highly breathable, suitable for the coverage and reproduction of nitrifying bacteria, so as to improve the water clean. The natural look and feel create an engaging environment that encourages your pets to explore and stay active, promoting better health and vitality The ceramic jars measures approximately 2"-4", fit in most fish tank. The bottom of these ornaments are flat, so once you place it underwater, you don't have to worry about it floating on the surface Aquarium decor cave provide shelter, hiding spots for your small fish, shrimps, cichlid, hermit crabs. Betta fish loves it, swims in and out of it and even will rest inside at times. Vintage pot aquarium ornament is an attractive addition to your aquarium. Which make your tank look more vivid and change it into a beautiful scenery The thoughtfully designed entrance and size of the hole darken the interior, offering a sense of security and comfort for your pets. These ceramic pots enhanced privacy help your reptiles and aquatic creatures feel safe and secure, reducing stress and promoting a more natural and relaxed behavior in their environment The natural look and feel create an engaging environment that encourages your pets to explore and stay active, promoting better health and vitality. It is safe for both freshwater and saltwater.Fired at high temperature, it will not fade, nor will it weather because of long time, and with time, it will become more historical