Made with temperature-resistant borosilicate glass, food grade silicone and PP. Orthodontic thumb-shaped nipple is more readily accepted by babies. Anti-colic vents allow your baby to drink without gasping for air or drinking bubbles. Off-centre silicone nipple allows for feeding in a natural, upright position. 100% medical grade silicone nipple mimics the feel and flex of a mothers breast. Ergonomic design is easy and comfortable to hold, with non-slip grooves. Clearly marked measurements to ensure accurate feeding. Dustproof cap protects from airborne nasties. Safe in freezers and boiling water. Compatible with most Gen. 3 attachments. BPA, PVC and phthalate-free. The Haakaa Gen. 3 Glass Baby Bottle is designed to provide the most natural feeding experience possible for you and your baby. The orthodontic thumb-shaped nipple mimics the shape of a mothers nipple during breastfeeding, and the offset position allows you to feed your baby without completely inverting the bottle. Our glass bottles are made from temperature-resistant borosilicate glass, making them safe to heat and freeze and perfect for storing expressed breast milk! The Gen. 3 Glass Bottle is ergonomically designed to be held easily and comfortably during feeding.