I have no idea how to build such a bright lamp in a high enough quality for so little money. The aluminum case is perfectly edited and beautiful black anodized. The lamp is measured 10W, ie from the 3 batteries are drawn almost 1A. The burning time with 3 pieces 2Ah batteries is about 2 hours, then the lamp will slowly darken. Whether it is the lamp betriebt with 2 or 3 batteries no matter the brightness is equal. 3800LM are of course a lie, when compared with other bulbs I guess the part to 700-1000 lumens. The light output of these lamps corresponds approximately to a good 50W halogen reflector. The light color is cold white, although the color rendering is reasonably neat. The ribs on the lamp head provide good cooling for continuous operation without problems. The rear battery spring is fitted with a solid brass contact, thus there are no problems with loose contact.
The screw-in lamp bulbs with a diameter of 51mm and is 47mm long. This is only slightly more than a standard halogen reflector. You can easily remove the reflector unit and thus - assuming some skill - upgrading existing underwater lights or lamp heads. Who will replace eg a 50W halogen bulb gets same light output and more than 5 times the burn time with the same battery. Compared to 10W Welch Allyn HID lights this LED lamp delivers more than twice as much light with much better color rendering.
Of course one could deduct a star for misleading description, but with today require 3800LM LED technology at least 30W electrical power. At 30W, the batteries were empty after 20 minutes and the heat would destroy everything. Therefore clear beforehand that 3800LM can not be, and that's why I prefer from no star.
