The delivery was fast and good, the transformer is working properly and pretty small - but he does not work with 12 V LED lamps (GU 5.3, 4 pieces per 5 watts). After a few seconds the lights begin to flicker and then go for a few seconds completely. Temporarily managed a normal halogen bulb between the LED lamps remedy. However, after several hours of operation the flickering began again. The change of poles in the wiring brought no improvement. I then sent the transformer back. Pity about the time.