Comparison Chart: Material SiliconeMAM Size 2 Medium Flow Bottle Nipple, 2 Months, 2 Pack SiliconeMam Silk Soft Nipples Fast Flow 3 SiliconeMAM Bottle Nipples, 2 Pack SiliconeTommee Tippee Natural Start Baby Bottle Nipples, Medium Flow, 3 Months, Breast-like for a Natural Latch, Anti-Colic Va...