Fully Submersible, Fully Waterproof and UL Certified Heater suitable for both fresh and salt water aquarium set ups featuring TrueTemp technology TruTemp dial with readjustment ring allows the user to calibrate the heater for a precise temperature reading Thermo safety control - enables running dry protection; heater will shut off when out of water Made of shatter-proof glass Precise temperature regulation Extra long cable of 5`6" Includes clamp with 2 suction cups Simple and safe recalibration (+/- 2 degrees)Made in Germany - For Fresh and Saltwater Tank Size Power Needed Heater Length 7-16 gallons 50 watt 9" 16-26 gallons 75 watt 10.2" 26-40 gallons 100 watt 12.2" 40-53 gallons 125 watt 12.2" 53-79 gallons 150 watt 13.4" 79-106 gallons 200 watt 15.7" 106-159 gallons 250 watt 17.3" 159-264 gallons 300 watt 19.6"