The Allen Bradley 40BY1-4000 Photoswitch Light Source is an accessory component designed for the Series 4000 LED control modules, providing a reliable and efficient illumination source for photoelectric sensing systems. It functions as an independent light source within a two-piece photoelectric interrupter or light switch, ensuring precise light emission for accurate object detection and signal interruption. Built for durability and optical stability, the 40BY1-4000 supports consistent performance in automated sensing environments. In North America, Europe, Asia, and worldwide installations, this Photoswitch light source could potentially be utilized in systems requiring dependable standalone illumination for high-precision photoelectric control.