Let’s just say I have tried MANY different formulas and bottles to help with my daughter’s reflux. We finally found a formula that has helped which is Enfamil AR. This being a thicker formula, many bottles are already out of the question. We were using Philips Avent Natural Response and she was doing so good with those for a while but then she started spitting up so much. At this point she’s figuring out how to crawl and wants to drink her bottle while on her belly but hasn’t gotten down the tilting the head back to get the milk yet. I saw these bottles on my tik tok and decided to give them a shot so she could be able to drink her bottle on her belly and all the air is out of the bottle so it helps with her reflux also, she can hold it! No more putting handle sleeves over bottles (iykyk). Day 1, I already noticed a difference in her spit up and she took to the bottle immediately! We’re now about a week out and she loves them and I love them! The only cons I have (which aren’t really cons) I wish there was an even bigger bottle than 8oz, maybe an 11oz? My daughter is 7 months and is drinking 6 oz, so a bigger bottle would be nice when she starts drinking more. This bottle also has a lot of parts, I don’t really mind it because it helps my girl so much!