Metal Detecting: Night Vision Lithium Light

Over on ebay you can buy a light which is advertised as a Night Vision Lithium Light for Metal Detecting. I suppose it must be intended for when they want to go under dense low-hanging vegetation on heavily overcast days.
"This is a great alternative to the traditional head light or flash light which you strap on your head. This light comes brand new & complete with batteries. Lightweight, compact and made to take plenty of rugged treatment, the 5 LED cap light is powered by 2 lithium coin cell batteries for use up to 96 hours. Ultra bright white from 5 LED bulbs with 100,000+ hours or burn time. Completly water resistant, the 5 LED cap Light attaches under the brim of a cap for a number of hands free tasks". Oddly enough the same guy is selling the same product to metal detectorists for 99p, while he's posted them in another section for the huntin', shootin', and fishin' crowd for GBP 4.99. I wonder why that might be?









Left, American pays to be an "Upper Class Twit" for the week, Right, fairly typical UK metal detectorist .