Global Series Sounder, Multi-Voltage, Ex d, U-Bracket Mount - Supports 3 operational voltages: 24VDC, 120VAC 50/60 Hz, and 230VAC 50/60 Hz. Optional 316 stainless steel ratchet adjustable mounting U-bracket (Field installation required). Gain control. Non-metallic corrosion-resistant design. 15 Watt