From the Rigid Industries website:
“Among RIGID's most popular product lines, the E-Series benefits from RIGID's Midnight Optics. Utilizing our exclusive spot optic with a transparent black enamel coating, our Midnight Optics take the subtle blacked out look seriously featuring black oxide hardware. The Midnight Optics enable RIGID to disappear during the day while still providing powerful LED technology to light up the night. Own The Night with RIGID's E-Series double row LED light bar.”