One used (only for few months) Eheim Jager 3602 Trutemp Submersible Aquarium Heater- 50 W. Ideal for use in an EVO 13.5 aquarium tank or similar size tank.

Wattage: 50W
Tank Rating: 7-16 gallons
Precise temperature adjustment from 18 up to 34 °C
Simple and safe recalibration (±2 °C)
Temperature control accuracy ± 0,5 °C
Heat kept at a constant level
Heating function is indicated by a control lamp
Completely submersible (watertight)
With automatic dry run shut-off (Thermo Safety Control)
Handy cable length ca. 170 cm
Suitable for fresh and salt water