The Pink Feeder Teat allows no more fluid to pass through it than a cow’s udder naturally would, allowing the calf to suckle more intensely than conventional technology. The Pink Feeder Teat’s unique internal collapsing flap-valve holds the milk in the teat making it much more responsive to the calf’s needs. It is designed to function like a real cow’s teat, moving all the time while the calf is suckling, never closing in its relaxed state. There is a milk opening on each side of the nipple, situated so that the crown of the nipple remains intact. The teat is leak resistant even when used at the bottom of a milk container. Pink Feeder Teats pull through, most standard calf feeders, including tube or gravity feeders with a hole size of 3/4”. Black teats are UV-protected for long-lasting performance while under direct sunlight for long periods of time.