Make your friends’ aquatic home even “betta” with the Hydor Micro & Mini Aquarium Slim Fish Heater! This narrow heater can be fully submersed in the tank—even beneath aquarium gravel—to conveniently fit anywhere without disturbing the fish. Whether it’s a glass, plastic or acrylic tank with fresh or salt water, this product is fin-tastic for creating a more livable environment. This sop-fish-ticated technology makes the tank warmer than the ambient room temperature—and all you have to do is plug it in!