The DUO call indicator is a robust and reliable device designed for use in industrial and professional environments. It features clear optical signaling via a colored dome, available in various colors – including orange (00), green (10), clear (20), red (30), and yellow (40). The choice of dome color allows for individual customization to meet specific requirements, such as visual identification in production environments or distinguishing between different call sources. The devices are designed for an operating voltage of 230 VAC and are ideally suited for use in telecommunications systems where reliable and visible call signaling is required. The simple installation and clear design make the DUO a practical solution for B2B users who value efficiency and functionality.