Not stupid at all.I learned about it myself here. It is a thread conditioner you run your thread through. I keeps it from fraying and tangling and makes it easier to sew and thread your needle..It comes in a little blue plastic box. Joannes carries it by the needle threaders. It is usually about $3.49, and lasts forever!! I used to use bees wax to condition my thread, but this is 1000 times better.