Japanese Omelette Pan

Japanese omelette pans are rectangular, because Japanese omelets (or tamagoyakiki) are rolled. In order for the dish to keep a consistent shape, the pan needs to be rectangular. Look for quality non-stick coatings and a sturdy handle. Too many Japanese omelet pans are considered gadgets, and are not well made.
Japanese Omelette Pan:

Japanese Omelette Pan Pictured above: MyLifeUNIT Japanese Omelette Pan with Spatula, Nonstick Omelet Pan Tamagoyaki Egg Pan (Green)