Review on Highly Luminous 15-SMD 2835 Chipset 212-2 211-2 LED Car Bulbs, 42mm Festoon Bulbs, DE3425 DE3423 Replacements for Car Interior Dome Map Courtesy Lights, Set of 4 in Blue by Kyle Herrera

Three 42mm cords used in a 2005 Ford Crown Victoria - one in the main dome light and one in each of the rear reading lights. They're bright enough - definitely brighter than the original incandescent bulbs - and run a lot cooler. Whiter light is a bonus. Along with another type of spare bulb in the map light, the interior of my Vic is well lit at night, just the way I want it. I can't say anything about durability yet. The structure seemed solid. The heatsink did its job and they really aren't polarized, which is nice - no trial and error to get them to work properly. I also bought the 31mm vanity mirror version but it turned out to be the wrong one. The bulbs are not to blame - I had inaccurate information. I tested them and the smaller bulbs were just as good as the larger version, just a little less bright.