Fire Alarm Bell 8 Inch 120 Volt Fire Bell 8" 120 Volt AC (UL) Often used as a school bell, or in hotels, our fire alarm bells have been in service for 30 years. Back Box sold separately. Be sure to choose the alarm bell with the correct voltage. Indoor and outdoor installation. Argco is the bell store for professionals. Rated Current: 25mA - Sound Level: 95 dB