The Nalgene Wide Mouth Water Bottle Replacement Cap is a high quality and durable cap made in the USA. The 16 oz. Wide Mouth Cap fits Nalgene 16 oz. Wide Mouth Bottles. The 32 oz. Wide Mouth Cap fits the Nalgene 32 oz. and 48 oz. Wide Mouth Bottles. This high quality and durable cap comes in multiple colors to choose from so you can best match your bottle.