A quality smoke detector with integrated fixed 135 F and rate-of-rise heat detector. Provides triple protection against fire. Must be wired into a security system that has power failure backup. This detector does not have internal battery backup or a built-in sounder. Manufacturer's part number ELE-541CXT. The National Fire Protection Association requires that you use an end-of-line (EOL)relay to supervise 4-wire smoke alarm sensors. We offer the following EOL sensor: