The bottle body is made of transparent and heat resistant borosilicate glass The bottle body is smooth, it is not easy to accumulate milk scale, easy to clean and it is not easy to break under high temperature such as pouring boiling water The compact double handle is convenient for baby to hold with automatic straw which can make baby easy to sep milk in any position. Soft base and soft collar can enhance the impact resistance of glass bottle body. Vented soft and flexible nipple design helps reduce colic, gas and spit-up Safety : BPA Free How to use: Hand-wash the new bottles with soap and lukewarm water. Sterilize the bottles in hot water for 5 minutes. Open the cap and nipple and fill the bottle. Secure the nipple in place and feed the baby. After use always wash and sterilize the bottles to keep the bacteria away. Proper sterilization of bottles will help prevent infection-related illnesses in children. Caution & Warnings: Store the clean and dry bottles in a cool and moisture-free place Replace the teats periodically Store the bottle away from direct sunlight Never leave a child unattended while feeding. Check for cracks and breakage before using the glass bottles Ingredients: BPA Free