The small containers in this pack are optional accessories for your K400 Artisan Stand Mixer. The BPA-free containers have airtight lids and are ideal for storing sauces, homemade soups, dressings, dips or baby food. You can place the containers in this expansion pack directly on the blender base to blend. The asymmetrical blades chop and process even hard ingredients like nuts, fibrous vegetables and frozen fruits to a smooth consistency.