BUY. THESE. BOTTLES. You will NOT regret it, if you have a very fussy, crying, red faced little one that has an upset tummy, try these bottles out. My baby for the past 2 weeks had been crying and screaming with an upset tummy because of colic, and I was really at my wits end. Unfortunately the bottles I had used before Playtex was marketed as "anti-colic" but that wasn't true. My mom and grandma recommended these bottles because when I was a baby, I also had colic and the drop in nurser bottles worked like magic. My grandma purchased them as a gift and let me tell you, after using them 2 days its like a complete turnaround with my baby. He finally has relief! Thank you Playtex!