Based on your question about 4 spark plugs, I would recommend the Autoshop Ngk Spark Plug BP6ES X 4 for R106. This is a great value option that directly matches what you asked for - a set of 4 spark plugs. The Ngk brand is very reliable and these plugs will help keep your engine running smoothly. Please let me know if you need any other details! I'm still learning so my search results may not be perfect, but I'm happy to help narrow things down for you.
