The numerical designation is a reference to the three cartridge-mounted AAA batteries that operate the 21 100,000-hour-life LEDs, each producing 12,000 millicandela, combining to deliver a bright white light. Easily illuminating channel markers at 200 yards, it provides plenty of light in a dark engine room, when illuminating a dark anchorage or foredeck or for reading under the blankets.

A rubber On/Off button is at the base of the water- and shock-resistant, anodized aluminum case. At three inches long by one inch in diameter, it weighs a mere five ounces. Batteries are included, as is a convenient belt-mount holster and a 30-day money-back guarantee.