The Allen‑Bradley 855E-00XN3 is a 50 mm control tower stack light module that provides a steady green indicator when used as a No‑Lamp Module with a separate lamp unit. It is rated for 0–250 V AC/DC operation, and the “No‑Lamp Module” designation means the light source is not included with the base module. Designed for industrial signaling, this green, steady stage of a 50 mm stack light is installed in control panels to communicate a normal or go condition at a glance.
