Cortelco · Home · VoIP Helios IP Safety - 1 button Product Description Maximum resistance to dust, water and mechanical damage. High level of comprehensibility and high volume in noisy environment. Striking colour for easy identification under poor lighting conditions. Backlit anti-vandal button made of stainless steel. Integrated relay for controlling external devices. Reliable communication under any conditions. Simple installation and configuration. Other elements can be added to expand the system with ease.