Allen-Bradley 855T-B10FN4 Stack Light Module

Allen-Bradley 855T-B10FN4 is a 70 mm red flashing incandescent stack light module from Rockwell Automation's 855T control tower signaling family, designed to mount on industrial equipment and control panels to provide a clear status indication. The B10FN4 variant features a red lens and is powered by 120 VAC, signaling faults or warnings with a rapid, attention-grabbing flash. This signaling module is built for rugged factory environments and integrates into Allen-Bradley panel towers to convey machine state, process alarms, and operating conditions at a glance, helping operators quickly identify when intervention is needed. Typically used on conveyors, presses, and packaging lines, it serves as a visible, differentiable indicator in multi-color signaling stacks.