Nuby Standard Neck NON-DRIP NIPPLE * Vari-flo Valve allows child to control liquid's flow rate. * Silicone Non-Drip Nipple. * Anti-Colic Air System prevents ingestion of air by baby. # The unique shape of the Nuby Contour Non-Drip Bottle contours to child's hand. # Teething nubs massage and stimulate gums.