Playtex Drop In Liners for Nurser BottlesOnly Playtex lets you Skip the Trial and Error.At Playtex, we make it easy to mix and match bottles and nipples to find the perfect fit for mom and baby. Instead of buying bottle after bottle, Playtex offers a versatile and easy-to-use feeding system.To reduce the trial and error on the bottle journey, Playtex introduces the first Nipple Variety Kit to match your baby’s unique preference right from the start. The four distinct nipple shapes and sizes are compatible with each of our Playtex bottles - Playtex VentAire and Playtex Nurser with Drop Ins Liners, both uniquely designed to reduce colic.Only Playtex lets you skip the trial and error of Infant Feeding. Give your baby the best right from the start, in 2 easy steps. Supplement FactsDimensions- 2.2 x 6.4 x 4.4 inches DirectionsFailure to follow the instructions below may cause the liner to burst, spilling hot liquid & causing injury. Do not boil any liquid, heat in microwave oven or sterilize inside the liner or Nurser. Do not heat Nurser directly on a heat source. Do not shake or mix contents of Nurser while liquid is hot. Do not give Nurser to baby if hot to the touch. To avoid injury, do not let baby walk with Nurser. Do not put baby to bed with Nurser. Prolonged contact with liquids may cause severe tooth decay. Ask your doctor or dentist for more information. ExpirationThis product has no expiration date or the manufacturer has not provided an expiration date.