Playtex Drop-In Disposable Bottle Liners - 4 oz - 100 count Playtex@ Drop-Ins@ liners are pre-sterilized and guaranteed to be the strongest you can buy! Drop-Ins pre-formed shape allows for one hand holder assembly, making it quick and simple to prepare a bottle even while holding baby! Drop-ins system Playtex@ Drop-Ins system features pre-sterilized, disposable liners that collapse as baby feeds so no air gets into the milk. This system has been clinically shown to help reduce gas, colic, spitting up and support baby’s natural feeding rhythm. The Playtex@ Drop-Ins System has been shown similar to the natural sucking, swallowing and breathing patterns of breastfeeding. When feeding time is through, simply dispose of the liner - no clean-up necessary! 100 count 4 oz liners