Ribbed Rings: Give The Teat Correct Elasticity And Texture, making It Similar To The Nipple Large Base: Ensures maximum support For Baby's Lips & Helps Sucking. Correct Length: Similar To The Nipple, The Teat Stretches To Twice Its Length During Sucking. Colic Valve: Avoids The Swallowing Of Air & Helps To Reduce Colic, Hiccups & Regurgitation.