Designed in conjunction with breastfeeding experts, the revolutionary new Tommee Tippee Closer to Nature easy-vent teat mimics the natural flex, movement, and softness of a mom’s breast, to make switching between breast and bottle easier than ever before. The unique shape of the Closer to Nature easy-vent teat encourages your baby’s natural feeding action so that switching between breast and bottle becomes second nature. The Closer to Nature bottles have been designed to be held in the most natural positions during feeding and can be held in 3 ways: cradled comfortably in the hand, gripped in the same way as a traditional wide neck glass bottle and held from the base; making feeding comfortable for both mom and dad. With its unique easy-vent anti-colic valve which you can actually see working, the Closer to Nature glass bottle is at the heart of an entire breastfeeding support system which also includes a breast pump, sterilizers and accessories specially created to help you combine breast and bottle feeding. The glass bottle made from high-performance borosilicate glass. It’s a very strong and durable material with excellent thermal properties. It’s lightweight and shatterproof with an anti-slip base.