Federal Signal patent pending G-Series sounders are available in explosion proof "Ex" versions and increased safety "Ex de" wiring box versions and are certified for gas Group IIC environments. The G-Series sounder can be wired to perform two separate functions. A single tone can be selected via a rotary switch; once power is supplied, it will sound the selected tone. Alternatively, multiple tones can be selected remotely by choosing the appropriate combination of inputs. This allows a unique sound to match a specific alarm condition or to be used to escalate an alarm condition. The G-Series sounder can be combined with all other G-Series audible and visual products in several custom configurations. Custom configurations can be ordered directly from the factory. Optional coupling kits, which allow limited field fixturing, are available.