Review on DE3175 Festoon LED Car Bulb, 31mm 1.22in, Super Bright White, Pack of 6pcs - Ideal for Interior Map, Door, and Dome Lights - Fit for DE3021 DE3022 LED Car Bulb by Warrick Infinite

They are very bright and work great. My application is dome (1) and headlight map (2) in Subaru Legacy 2016 -Premium. Installation was tedious. It was very difficult to insert these LED lamps between the terminals in an outlet. I may have ordered the wrong size but the literature said I need DE3175 garlands. I think I understand the issue - if you compare the old and these new bulbs, the Legacy bulbs are the same length from tip to tip as these LED strings. But the profile at the end is sharper on older lamps, as opposed to the "blunter" end on LEDs. This difference in profile caused LED bulbs to sit differently in their terminals. They tend to slip. I hope these LEDs don't vibrate off their sockets. I deducted a star for the installation and inaccuracies during installation, but the lamps work perfectly. Note. Remember that LED bulbs are diodes by definition. A property of diodes is that they only allow current to flow in one direction. So you have polarity. If you try them and they don't light up, just rotate them 180 degrees and check again.