A journalist recently tested the Ninja Double Stack XL SL400EU air fryer, evaluating its design and performance. This 2-drawer, 6-in-1 air fryer has a total capacity of 9.5 liters, divided into two 4.75-liter drawers. Designed for large families or gatherings, it allows users to cook up to four different types of food at the same time. The air fryer is constructed from plastic and stainless steel, with a gray finish and a weight of 12.8 kg. Its vertical design helps save countertop space, and the control panel is located on the right side, described as intuitive and easy to use. The device comes with two drawers, two baking sheets, two cooking grids, a recipe booklet, and a start-up guide. It has a power rating of 2,470 W and can operate within a temperature range of 40°C to 240°C. The six pre-programmed functions include Air Fry, Max Crisp, Roast, Bake, Dehydrate, and Reheat. The drawers and accessories are compatible with dishwashers, and the non-stick coating makes cleaning easier. The air fryer is available for purchase at 269.99 € on the Ninja website and comes with a 2-year warranty. Each drawer features its own heating element at the back, allowing for independent cooking at different temperatures and durations. The SYNC function enables both drawers to end cooking simultaneously, while the MATCH function copies cooking settings from one drawer to the other. During testing, the air fryer operated at about 50 decibels, which is considered a normal noise level for such appliances. Users found the device easy to handle, even for those unfamiliar with air fryers, though some foods required stirring for even cooking. The air fryer's performance was described as successful and straightforward, though the fries produced were less crispy compared to traditional fried fries but had less fat. The device is considered to offer a good balance between price and performance, despite being heavier than some similar models. Its main strengths include the space-saving vertical design, large capacity, versatility, and the useful SYNC and MATCH functions. However, users noted that stirring food during cooking was necessary, and the weight could be a drawback for some.