The six water bottles in the PEARLPET set are tested to guarantee that they are constructed of food-grade materials and are free of BPA. They are robust, resilient, and long-lasting. These bottles work well in the refrigerator and in the freezer. Because the bottle is translucent, you can monitor how much water you're consuming. The bottles are made with the newest designs and a circular lid that fits snugly to prevent water leaks. These bottles are convenient to use on the go and fit neatly into gym bags or office backpacks.