Orlushy Submersible Aquarium Heater,100W/150W/200W/300W Fish Tahk Heater with Adjust Knob Thermostat 2 Suction Cups and Free Thermometer Suitable for Marine Saltwater and Freshwater200W aquarium heater is suitable for 40 to 60 gallons aquariums,Length 11",voltage 110 120V, power cord is 6ft, please choose the right wattage aquarium heater according to our size chart. It shows an area to adjust the temperature. It's not exactly accurate but it turns easy and can be adjusted at small intervals. Explosion Proof: 2mm thickened quartz glass,can be used in fresh water and salt water aquariums,easy to hide in the tank. Precise