The Drop-Ins Premium Nurser is a sleek, contoured bottle that holds Drop-Ins liners, which collapse for an air-free feed. This unique system has been clinically shown to help reduce gas, colic, and spitting up. The pre-sterilized, disposable liners collapse to keep air out of the bottle and your baby's system. After each feeding, the liner is discarded, so there is one less thing to clean. Contains: 1 8-10 OZ Nurser, 1 NaturaLatch Slow Flow Silicone Nipple, and 5 Drop-Ins Liners - Yellow.