Easyplug heaters provide strong heating power in a compact, ready to use package.  The simple easyplug fitting provides a plug and play package.  Available in 316 Stainless Steel for freshwater use, or Corrosion Proof Titanium for saltwater use.  Over the side heaters hang on the side of a tank, while bottom heaters rest on the bottom.  Be sure to also purchase a controller along with the heater.