Add some natural, rustic beauty to any aquarium with the Penn Plax Mushrooms on Rock Aquarium Decor - Medium. This classic piece of aquarium decor is crafted of fish-safe, non-toxic resin and offers plenty of room for fish to hide and openings to swim through. Made of non-toxic and fish-safe resin. Intended for both fresh and salt water. Accented with brown mushrooms. Creates a natural-looking environment to your aquarium. Dimensions: 5.5L x 4W x 7.5H in.