A range of external sounders with options for radio, wired and decoy. Common enclosure for the entire range: impact-resistant polycarbonate construction in a choice of 3 colours: blue, amber and red. An engineer-friendly unit with a self-supporting lid, built-in spirit-level and revolving fixing holes for ease of installation including on uneven surfaces. High-power comfort LEDs provide reassurance for the user. The radio variant is designed for use with i-on and legacy 868 MHz systems. The wired variants are also compatible with third-party control units.