The ABB ML1-100L is a 22.5 mm blue pilot light operator head designed for easy integration into control panels. This component meets multiple NEMA ratings — 1, 3R, 4, 4X, 12, and 13 — ensuring reliable performance in a range of environments, from indoor control rooms to harsher outdoor settings. Keep in mind, this unit requires the addition of a head, contact block holder, lamp block, and lamp to be fully operational. Sometimes called 320500306182, the ML1-100L is distributed by BSP Automation, making it a solid pick if you need rugged and dependable signaling in your setup. It’s a real workhorse for your control station needs.