Nalgene BPA Free Tritan Wide Mouth Water Bottle Large opening on wide-mouth bottle easily accommodates ice cubes, fits more water purifiers and filters, and makes hand-washing a breeze. Attached Loop-top never gets lost and screws on and off easily. Printed graduations let you keep track of your hydration. Made from Eastman Tritan copolyester that is manufactured without BPA. Resistant to staining and retaining odor.