The BlueLIne Biotherm Heating Elements are constructed from titanium and use premium components to provide precise and reliable heating when paired with our Biotherm Heater Controller. Simply plug the Biotherm Heating Element directly to the switched 110v A/C outlet on the Biotherm Heater Controller to create the ultimate in automatic aquarium heat control. * Requires controller for proper operation Element Size Watts | Length | | 250w Element | 12" | | 500w Element | 13" | | 1000w Element | 15" | |