Twist lock with loop to secure the lid. Bbpa free. Capacity: 1 liter. Material: plastic.PRODUCT DESCRIPTION The practical bottles for all applications. Each Opening is 09 mm. Thanks to the narrower neck, they are more splash-free to use than the wide-necked bottles. Of course as well as being virtually indestructible, it is guaranteed to be leak-proof and really great for school, Camping, Hiking, cycling, Outdoor and free time.