The package includes 2 bottle pacifiers. Bottle-specific nipple designed to reduce gas, discomfort and colic symptoms Award-winning nipple similar to mother's breast for natural grip Unique anti-colic ventilation system removes air from milk. Advanced Anti-colic Baby Bottle Pacifiers are only compatible with Advanced Anti-colic feeding bottles. Medium flow and fast flow options are available. It is BPA free and phthalate free. QUICK START: Before use, wash with warm soapy water, rinse with clean water and sterilize. Assemble your bottle as shown in the figure. While connecting your bottle, you should make sure that the gaps in the silicone are not blocked by holding the valve towards the light. If it is clogged, gently rub it between your fingers to let it open again. If the valve is clogged, your bottle will not be ventilated properly.