We get a lot of questions like: "What is the ‘functional’ difference between these two different lenses. The TN4 appears to be what is installed on my two 914s, but I’m curious about the TN1-TN2 style. Different / better beam pattern?"

Here are a couple of resources: 

  * [[http://www.p914.org/p914_lenses_fog.htm|Porsche 914 & 914/6 Fog / Driving Lights]]
  * [[https://www.early911sregistry.org/forums/showthread.php?41891-Needed-SWB-Driving-Light-Info|Horn Grill Fog and Driving Lights]]

We'll keep adding to the TK Wiki as we learn more.