Here it is claimed in some reviews that upon delivery partly already some LEDs do not work or that it already comes to failures after a few weeks. This I can confirm but so (at least for my supplies) NOT. For me, all the LEDs are working properly to date. The prerequisite is of course that this correct direction with a direct current transformer (or AC with rectifier) are operated. Because LED lamps always have a positive and negative poles. Upside is installed namely nothing except the AC transformer, then with 50Hz as in TV: o)
I now have another 20 pieces ordered because the luminosity is stronger than that of a 10W halogen lamp!
One star less **** stars because a single LED in a light bulb flickering ...