The LuvLap Essential teats are 100% Liquid Silicone and have an anti-colic valve that vents air into the bottle, preventing any air from entering the baby's tummy. The teat has spiral grooves at the tip, which encourage peristaltic suckling, and help the baby get a comfortable latch, ensuring a stress-free feed every time. The grooved teats and superior silicone quality ensure no nipple collapse, helping in an uninterrupted feed.