Made from durable Polypropylene (PP) material, this bottle is durable and light-weight; ideal for both indoor and outdoor use. The ultra soft silicone rubber teat, with its double thickness, ensures the ideal softness and elasticity for your baby to latch on comfortably and easily. The shape fits perfectly onto your baby's tongue, allowing smooth tongue movement and minimizing air intake. Features: Slim Neck Bottle Made from PP (polypropylene) which is durable and lightweight Peristaltic Nipple is ultra soft and flexible to allow for natural and smooth tongue movement. BPA and BPS FREE Air Ventilation System (AVS) reduces intake of gas, a potential cause of colic.