The LED spots processed qualitatively good, look good and are very inexpensive. Have changed the AC transformer and replaced by a small DC transformer 18W (9cm long, just under 9) with the lights, the LED spots completely flicker-free. Almost all DC transformers are stabilized at 11,5Volt to prevent voltage spike so the LEDs are not destroyed. The 3Watt spots, however, are only comparable with 20W halogen but 4 LED spots light up a room 20 square meters of completely good. Am well pleased with these LEDs u. They would buy at any time again. Long-term experience with these lamps I have not until now. As always, fast delivery through Amazon.