Allen-Bradley 855T-B24DC4 Stack Light Red With Sound

The Allen-Bradley 855T-B24DC4 Stack Light Red With Sound is a 70 mm Control Tower signaling module designed to deliver a clear red visual cue and audible alert on industrial equipment; part of the Rockwell Automation 855T family, it’s built to mount in a vertical tower alongside other light modules to indicate machine states, faults, or process events. This variant uses a black housing (B) and supports 24V AC/DC input, combining a steady incandescent red lamp with an integrated sound module to provide simultaneous light and sound signaling without requiring separate devices. The 855T system is specified for stacking up to five light modules in a single tower, and when a sound module is included, only one sound module per stack is permitted, ensuring predictable signaling behavior across complex panel configurations. Ideal for automation panels, conveyors, and process lines, it offers a compact, standards-compliant signaling solution that can be expanded with additional colors and modules from the same family to create a comprehensive status indicator system.