Made with temperatureresistant borosilicate glass food grade silicone and PP Orthodontic thumbshaped nipple is more readily accepted by babies Anticolic vents allow your baby to drink without gasping for air or drinking bubbles Offcentre 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 nonslip 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 phthalatefree