• 6" (152 mm), 8" (203 mm) and 10" (254 mm) gong sizes
• 
  
• Heavy duty die cast housing
• 
  
• Rugged, compact mechanism
• 
  
• Rated for outdoor use with optional back box
• 
  
• Under dome mechanism
• 
  

The Edwards Fire Alarm Bells are diode polarized, vibrating bells designed for use with fire alarm control equipment. The gongs are made of select, alloy steel to sound the loud, resonant tone required in fire alarm systems. They are epoxy powder coated red.

Supplied mounting plate installs directly on surface or on any single gang box, or on any 3 1/2" (89mm) or 4" (102mm) octagon, or 4" (102mm) square electrical box.

For outdoor installation, use Edwards Cat No. 449 weatherproof back box.

The 438D and 439D fire alarm bells are audible signaling appliances for installations that operate in conjunction with an installed fire alarm panel and detection devices.