Federal Signal Vibratone® Electronic Horn, Compact Heavy-Duty, Series: 350, 24 VAC, 0.9 A, 50/60 Hz, 110/100 dB, Indoor/Outdoor: Indoor/Outdoor, Specifications Met: ARRA Compliant|BAA Compliant|CSA Certified|cUL Listed|FM Approved|UL Listed, Panel/Surface Mount, -65 to 150 deg F Operating, Die Cast Zinc, Gray, 4 in W x 2-1/2 in D x 4 in H