Who needs labels and markers? These clever Medela bottle lids make it easy to date and track your pumped breast milk for storage and feeding, because each lid houses a dial marked with the days of the week and the time of day. Just turn the lid until the applicable day is showing, then line it up with the hash mark indicating when you pumped (morning, afternoon, or evening) or when you want the breastmilk to be fed. Makes breastmilk storage easier, and the lids are compatible with all polypropylene Medela breastmilk bottles. You can also set up the Labeling Lids so caregivers know which bottle to use next Labeling Lids are easy to set: just pull up on the outer section of the lid to unlock, twist until you find your setting, then push down to lock in place. The settings won't shift, even if the lid is jostled. Compatible with all of Medela's polypropylene breastmilk bottles. Top-rack dishwasher safe BPA-free