See below text for which Philips Avent products are compatible and which are not.
Are the Philips Avent Natural and anti-colic bottles bottles and nipples compatible with each other?
What is compatible?
The anti-colic bottle is compatible with the Natural nipple when used together with the Natural screw ring. The Natural nipple can be bought separately; the Natural screw ring comes with the Natural bottles. The Natural bottle is compatible with the anti-colic nipple when used together with the anti-colic screw ring. The anti-colic nipple can be bought separately; the anti-colic screw ring comes with the anti-colic bottles.
What is not compatible?
The anti-colic nipple cannot be used with the Natural screw ring. The Natural and Classic nipple cannot be used with the anti-colic screw ring.