This innovative design allows the individual elements within each set to be stacked together, occupying the absolute minimum amount of space when stored. There are 4 different sets available, each with it€™s own individual features. All sets are dishwasher safe, BPA Free and Food Safe. The mixing bowls have non-slip bases and easy carry handles. The small mixing bowl includes measurements inside for added convenience (milliliters and fluid ounces), and a spout for accurate pouring. The measuring cups 'snap' together securely.