A pizza knife is shaped in a semi-circular shape and is a great addition to a pizza lover's kitchen. It is often called a mezzaluna or rocker knife ("rock and roll knife"). It has two handles, one on each end of the blade, which is about 20 inches or so long. You use it by holding onto both handles and rocking it over your pizza. It cuts across your pizza in one rocking motion. One of the selling points of these knives is that your cut is clean, smooth, and precise. These knives can also be used to mince herbs and chop vegetables.