Generally, bottles are made of plastic, silicone ... that are called stage 3 or 4 for babies closer to age 1. There’s nothing wrong with keeping your baby at the slow-flow newborn nipple ...
Brown's Natural Flow baby bottles so coveted? They have a consistent flow rate and their design reduces colic by decreasing, gas, burping, and spit-up. They also have a very breast-like silicone ...