Material The fish heater is made from high-quality quartz glass material, and this mini aquarium heater is explosion-proof and crack-proof, ensuring its durability and longevity. Mini Design This mini heater is compact and space-saving, perfect for small aquarium, save more space for fish to move around. Ideal for tanks ranging from 1 to 5 gallons. Best Sealing & Safety Better sealing and safety performance ensure that this mini fish tank heater never leaks electricity or water, providing a secure environment for your fish. Precise And Constant Temperature With a power output of 25W, these small heater provides precise and constant temperature control at 78 , creating an optimal environment for your fish. Range of Application This fish tank water heater is suitable for aquaculture, freshwater, saltwater and tropical aquariums.