Reflux and colic are why most parents end up trying four different bottles before one sticks. VentAire goes at the cause. Check the age grading first, because this pack is not a newborn pack: the carton prints 3M+ and MEDIUM, with two of the three droplets filled on Playtex's nipple flow scale, so it is graded for babies of 3 months and older. Playtex make the NaturaLatch Comfort nipple in a slow flow as well. A patented vent in the base keeps air at the back of the bottle as your baby drinks, so no air mixes into the milk, and the angled body holds the bottle at the semi upright position pediatricians recommend for feeding. Playtex call that combination doctor recommended for reducing reflux, colic, gas, burping and spit up. The wide NaturaLatch Comfort nipple is soft silicone and shaped to encourage a proper latch, which is what makes switching between the breast and the bottle stop being a fight. Cleaning was clearly designed by someone who has done it at eleven at night: the bottle comes completely apart, and there are few enough pieces to put back together one handed. Three clear 9 ounce bottles in the pack, each holding 266 mL. BPA free, PVC free and phthalate free.