Installed in the stock headlight housing on my 2003 F250. The bulbs put out an attractive white color, they're indeed bright, but still pretty limited light coverage. The high and low beams still work properly, but the flash-to-pass by pulling back on the turn signal stock didn't make a dual beam like it should. Instructions are pretty easy to read. They do use the OE twist-lock to hold them into the housing.Pros:They're cheapThey're brightSexy colorSturdy and well madeThe cooling fans are very quietCons:Low field of viewNo flash-to-pass capabilityPretty difficult to get into the housingThanks for reading!