A featherlight, flexible silicone bottle with a triple-vent nipple — comfortable for tiny hands to hold early.
The Flexy is the most comfortable modern silicone bottle to hold, and the wide triple-vent nipple handles gas well. Babies transition to self-holding on it early because it's so light and grippy. It's a premium price for a single bottle and the flexible body means it can collapse a bit under vigorous drinking, but it's a lovely upgrade pick.