<p>The all new Cobalt Aquatics ACCU-Therm fully submersible heaters feature an easy to set thermostat with and ON/OFF indicator light that is Triac equipped that turns the heater on and of at lower voltage, and magnetic contacts that ensure positive contact and release of the rmostat switch every time. All of these features are have been engineered to extend life and reliability of the rmostat and ultimately the heater. The tube is made of Borosilicate glass for superior heat and shock resistance and surrounds a high quality ceramic heat radiator that provides even and the best heat distribution from the heating elements.</p> <b>Features:<br /><b> <ul> <li>Easy temperature setting </li> <li> Computer tested, accurate ?2 deg F </li> <li> ON/OFF indicator light </li> <li> Triac equipped thermostat turns heater on and off at lower voltage to extend life </li> <li> Ceramic heat radiator </li> <li> Borosilicate glass for superior heat and shock resistance</li> </ul></b></b>