They do not require a special transformer, they fit normal household wiring. I used them to replace the puck light under the closet, a not very bright mood light. They are very bright, bright enough to provide 5W, 7W work lights. There are two spots where I would prefer a lower light level, but the other 5 spots are very useful. If there are lower wattage bulbs available please let me know. Changing bulbs is so quick and easy that it was surprising compared to replacing a G8 bulb in a Puckβ¦