The ROMIRUS Bottle Screw Rings Replacement for Avent Natural Baby Feeding Bottle is a set of 3 rings designed to fit Avent Natural bottles. These rings are constructed from premium food-grade PP materials that are BPA and lead-free, ensuring they are safe for babies. They are heat-resistant up to 120°C/248°F and can be safely used in dishwashers and boiling water. Note that these rings are not designed to fit Avent's classic dome cap or replace the Avent Classic Collar Ring. This is an aftermarket product produced by ROMIRUS and is not associated with Avent. The package includes 3 replacement rings, but the bottle is not included.