This adapter Allows you to plug a clear plug (3GG-10) CDI to a "square plug" (3GG-00) harness 
 
This is great if your CDI has gone out and you can't find the one you need or you've found a great deal on a different year. Also great if your simply building a Banshee from a bare frame and are piecing it together.
 
How to use it: Just plug the adapter into the CDI then the harness into the adapter....thats it! DONE!