Pigeon Peristaltic Nursing Bottle RPP is made of high quality durable plastic, the streamlined shape makes it easy for mothers to hold and keep clean. Salient features of Pigeon Peristaltic Nursing Bottle RPP: Encourage baby's natural tongue movement. Ultra soft Silicone with its double thickness ensures ideal softness and elasticity so that your baby can latch on comfortably and easily. The shape fits perfectly onto your baby's tongue, allowing smooth tongue movement and minimizing air intake. Helps to adjusts air pressure inside the bottle. Specially designed projections at the base and the top of the teats allow milk to flow smoothly into the baby mouth. The adjustment of the air pressure inside the bottle minimizes air intake when feeding. Hence, baby will not swallow excessive air bubbles with milk.