Ninja Double Stack series air fryers are high-end devices that stand out among uniform competitors primarily due to their futuristic design. All models in the lineup are equipped with two baskets, but they are arranged vertically—one above the other—rather than side by side like other multi-cookers. As a result, the device is quite tall but occupies less space on the work surface. The control panel also has an unusual placement—on the side of the body, separate from the bowls. Thus, the series is aimed at large families who need to cook multiple dishes simultaneously without unnecessary space compromises.

The key technology of the series is DoubleStack Air Frying Technology: each basket is equipped with its own heating element and rear fan, ensuring 360° air circulation independent of the second zone. Additionally, each basket can be fitted with a panel that divides the space into two parts. Thanks to this, up to 4 different dishes can be cooked simultaneously with separate time and temperature settings in one air fryer. The Smart Finish and Match Cook functions allow either to synchronize the completion of cooking in different zones or to copy the settings of one basket to another.

The devices are quite spacious: the total bowl volume of the most compact model is 7.6 liters, while most other representatives of the series are 9.5 liters. Such a basket easily accommodates a whole chicken.

As for settings, 6 automatic programs are available: frying, air frying (oil-free frying), baking, Max Crisp (for maximum crispiness), reheating, and dehydrating (drying). In addition, temperature can be manually adjusted and an optimal cooking time can be set using a timer. The higher models include a Foodi Smart Thermometer with a function for automatically determining meat readiness without having to open the basket.