Summary

Drain Plug Holder for Harley-Davidson motorcycles. For those who are meticulous about keeping track of where each drain plug came from and to keep them from getting lost.
Each socket has a designated letter to each case:

"T" for Transmission
"E" for Engine
"P" for Primary

I personally use it at work every day when I drop the oils for a service. Great for removing the O-rings, cleaning the threads, and just have them at hand when i'm ready to reinstall them.