ONN-M4T USB LED Signal Tower Light 7 Colors Computer Control RGB Warning Light For Cash Register Inspection Machine Product Overview ONN‑M4T‑USB features a USB interface, directly connected to computer and controlled by serial‑port software. Innovative design delivers seven colors on a single layer (Red / Green / Blue / Cyan / Yellow / Magenta / White) through RGB mixing. Double PC lens produces soft, uniform light with better visual effect. Optional buzzer over 85 dB for
