The Playtex nurser with Drop-Ins liners allows Baby to switch easily between breast and bottle feeding. The pre-sterilized disposable liners collapse as Baby drinks, so she takes in less air and experiences less colic discomfort. Made from BPA-free silicone, the slow-flow nipple has a raised textured area that"s designed to help Baby latch on naturally. This four-ounce nurser includes five Drop-Ins liners.