Quantum Solid State Heater : Very accurate and very affordable, these heaters from Thermal Guard offer the best combination of value and accuracy. State-of-the-art Solid State heaters like our Quantum Solid State set the standard for durability and reliabilty and fine temperature control. Sensitive electronic control holds the temperature very close to set point. Insures consistent and accurate temperature sensing as well as readout. If your Halcyon, Aqua Queen or Sanctuary waterbed heater has failed, this is an excellent replacement.