NanoNine Uni-Steel Bottle is made of high quality lightweight stainless steel. NanoNine Sprint Steel Bottle is here to provide you refreshing drinks anywhere you go. Keeps you & your kids hydrated & hygienic with this lightweight sturdy model. Stainless steel body makes it more durable and safe for people and earth in comparison to plastics. NanoNine Sprint Steel Bottle can be used as a fridge bottle.