Each bottle a carabiner which you can put the bottle on your bag. Made of 100% food grade silicone passed FDA, LFGB test, durable and flexible enough to folding, foldable drink bottle are Non-toxic, BPA free and safe. Perfect for work, school, gym, running, hiking, biking, boating. It's easy to carry and anti-breakage. The promotional water bottle is available in a multitude of colors.