53 mm cap Fits Nalgene 16 oz. Wide Mouth Water Bottle Made in USA Available in multiple colors High quality and durable material The Nalgene Wide Mouth 16 oz. Water Bottle Replacement Cap is a high quality and durable cap made in the USA. This cap fits Nalgene 16 oz. Wide Mouth Bottles. This high quality and durable cap comes in multiple colors to choose from so you can best match your bottle. 53 mm cap made from high quality and durable material.