Features digital I-com circuitry, which provides great signal strength, this is easy setup! Use the colour sync to match the LED’s with your alarms. Receiver Features Digital I-com circuitry for great receiver strength Low Battery drain with Low Battery warning indication Receiver batteries are too low when the LEDs automatically begin to flash red every 2 seconds Multicolour LED’s with Colour Sync Easy Micron Registration Weatherproof sealed case Cone Speaker Removable Lanyard