System Sensor launched its conventional, two-wire heat detector, the 5151. The device is a combination fixed and rate-of-rise thermal detector designed to provide open-area protection with 50-ft. spacing capability as approved by UL 521. For local alarm indication, it includes two LEDs on each detector for 360-deg. visibility. The 5151 replaces the 5451 heat detector and carries the same electrical properties in a more modern package. The new housing matches other System Sensor conventional products, allowing for a consistent look throughout facilities.