FERMAX 3431 Universal Handset to replace 3393, 3399 Handsets

The Fermax 3431 Universal Handset is an audio door entry terminal designed for compatibility with a wide range of analogue door entry systems. Operating on 4+n and 1+1 wiring configurations, it serves as a versatile solution for both new installations and replacements in existing intercom systems. It supports standard door opening functions, audio communication with the entrance panel, and the option to integrate a second button for auxiliary functions such as stair light activation or secondary door release. This universal handset is equipped with a built-in electronic call tone generator and includes a mechanical call volume control with an off position. The internal electronic circuitry is engineered for high sound clarity and reliability, and the handset is housed in a compact, robust ABS plastic casing. Installation is straightforward, aided by an intuitive internal layout and included terminal guides for easy wiring adaptation.