It"s no mystery that the Penn Plax Pyramid Face Cave Aquarium Décor is one of the wonders of the aquarium world. This non-toxic, fish-safe pyramid is the perfect spot for little fishies to hang out. It"s crafted of plastic and won"t alter your aquarium"s chemistry. * Durable resin construction * Designed for both fresh and salt water aquariums * Non-toxic and fish-safe * Provides fish with an obstacle to swim around * Makes a perfect addition to your aquarium