Speco Technologies Nexus Contractor Speakers Commercial Line utilizes premium quality components to provide a network of sound and paging for even the most demanding commercial environments. The high-end NXC Series features heavy-duty, industrial metal back cans that provide component protection and safety while enhancing the speakers' full-range bass sound. Removable “Quick-Snap” connection terminals provide easy access and optimal angles for connecting speaker wire. A wattage selector dial simplifies transformer settings. Mounted security loops allow for a support cable run and ceiling support brackets are included. Most importantly, these speakers have met or exceeded the strict UL 1480 and UL 2043 requirements for fire safety.