Combined acoustic and optical alarm signaling device is EN 54-3 & EN 54-23 compliant, in red housing, and offers a selection of 32 signal tones including the DIN tone and other country-specific tones. All tones comply with EN 54-3. Tone configuration takes place via a 6-pin DIP switch. Up to two different signal tones may be activated. The optical signaling device with red signal lamp is suitable in accordance with EN 54-23 for square signal ranges W-2.4-6.0 and cylindrical signal ranges C-3-8.9 / C-6-8.2. Signaling device with flat base, suitable for wall and ceiling mounting. To help define your conventional Visual Alarm Devices (VADs) requirements in line with the EN54-23 standard, we have developed an easy to use online guide. Simply enter the room dimensions and ambient light conditions and the guide will help your device selection: http://www.kac.co.uk/EN54-device-chooser.htm