What is your favorite cooking "tool"??

What is your favorite cooking tool or item??

(The thing you really can't live without besides your knives??)

Besides the knives, I can't leave my "tool box" at home anymore....it has all my small stuff in it that I just might need......like graters, meat tenderizers, measuring spoons/cups, and some straggling recipes. Every once in a while, I will bring my recipe box & personal cookbook with me too.