The Closer to Nature Vented Bottle has been designed to provide optimum venting during feeding via a unique tube and valve system and easy latch on shape, which can help to minimise ingestion of air. Before feeding baby, check the heat sensing tube. If it is blue it is safe to feed; if it has changed to pink the milk is warmer than the recommended 37°C. The teat has a unique, easy latch on shape with soft natural feel silicone. Unique tube and value system to provide optimum vending during feeding Unique, easy-latch-on teat shape that promotes continuous feeding Soft, natural-feel silicone teat to make it easier to switch between breast and bottle Easy-hold bottle with slow-flow teat Bottle compatible only with Closer to Nature Teats for Vented Bottles (not Closer to Nature Easi-Vent Teats) BPA-free