ONN-M4-1 One-Layer RYG LED Stack Tower Light With 85dB Buzzer DC24V For SMT & Automation Equipment Product Overview Cost‑effective RYG tri‑color warning light for CNC & automation equipment ONN‑M4‑1 is a traditional‑style single‑layer LED signal tower light, integrating Red / Yellow / Green three colors in one lamp module for compact machine‑status indication. High‑brightness LED chips with low light decay, optional built‑in buzzer over 85 dB for audible alarm. Three kinds of