These products use three common methods: hot-air (air) poppers that pop without oil, electric stirring poppers that use a small amount of oil plus a motorized stirring arm, and a manual stovetop kettle that uses oil and a built-in stirring rod.
Typical per-batch yields in these listings are about 15 cups for an air popper and about 24 cups for a stirring electric popper; the stovetop kettle listings give a separate maximum capacity listed in liters/quarts.
Common built-in accessories include stirring bars/rods, serving lids that double as measuring cups, butter-melting trays, and recipe guides. Some models also add practical features like cord wraps and ergonomic handles for easier carrying.