Frequently Asked Questions How tightly to screw the ring on my Philips Avent bottle? Find out how to best fit the ring on your Philips Avent baby bottle. Assure the best fit The design of the bottle neck is such that there should be a gap (see picture below) between the glass bottle body and the plastic screw ring. If you feel some resistance when assembling the screw ring to the bottle, please stop screwing any further. The bottle is screwed tightly enough. Do not over-tighten the screw ring. This might lead to damage.