A 15L oven air fryer (also called a 15-liter air fryer oven or convection countertop oven) is a versatile multi-function appliance that combines air frying with traditional oven capabilities like baking, roasting, toasting, broiling, dehydrating, and more. Its larger capacity (around 15 liters / ~4 gallons) makes it suitable for families of 4–6 people, fitting whole chickens, multiple trays of food, pizzas, or batch cooking.