"Natural design from ChuChu Baby Feeding Bottle, The bottles are designed specifically for moms to enjoy fashionable styles. Natural and gentle design resembles plants. It makes moms feel organic. Super Cross Cut Hole Technology：World-wide patents applied. This adaptive structure maintains a suitable hole size that may be used until weaning. The super cross cut hole is usually closed, but only opened by the baby"s suction and teething power. It will not leak even if bottle tips over. Because ChuChu Baby"s teat resembles mom"s breasts, it can make an adjustment of the amount of milk flow controlled by the baby"s suction. It is made of transparent and tough Silicone. Anti-Colic：The air vent located on the side of the teat prevents the inside of bottle from becoming a vacuum. Any air adjustments by the cap are unnecessary and this structure dispenses just the right amount of milk sucked by a baby. Wide-Neck：The wide-neck bottle design cleans easily and the wide-neck teat shape is designed to be similar to the mom"s breast in order to prevent babies from getting confused when switching between breastfeeding and bottle feeding. Material：Tough heat-resistant glass bottle that does not get dirty easily. OK to sterilize by boiling water, with chemical agents or by microwave. Cap and hood are made of Polypropylene. Safe and secure bottles based on "Made in Japan" quality. "