Just for the battery system in a stack that is the best of the lamps! Add the ability to program the intensity and thus lengthen lighting ... and 3-stage programmable. Ok it costs a little expensive but the use is fully justified, especially since you will not have to buy battery. The last was in 2008 ... good life. The bulb died in December 2014 ... shame not to have found how to change it (only bad point because I do not like the consumable side that gives an expensive product - 1 star).
