Minimum visible distance is 3 nautical miles LED technology means ultra low current draw and no bulbs means no maintenance for an ultra long service life Multivolt 9-33 Volts DC technology is spike protected to +500 Volts DC and reverse polarity protected to -500 Volts DC Sealed light unit clips into mounting shroud for an ultra secure attachment Pre-wired with 2.5 meter of twin core marine cables