The Wheelock Eluxa weatherproof series EL3RMT / EL4XMT Multi-Tone Horn and EL4XMTST/EL3RMTST Multi-Tone Horn Strobe (and Amber) appliances are designed for easy installation with a pre-wire capable EL4XBB surface box or EL3RMP mounting plate. Eluxa Multi-Tone requires two circuits (NACs); one for the Eluxa LED strobe and the other for the Multi-Tone audible. In this way, the Eluxa Multi-Tone can be "coded" without affecting the strobe. In addition, Eluxa Multi-Tone offers a choice of eight different tones to select from. This includes a temporal T3 tone that can be synchronized.