VACUUM INSULATED:Keeps liquids warm for up to 6 hours or cold for up to 24 hours (iced) SAFE: Only 100% plastic-free bottles on the market; Baby Grows...Bottle Evolves™:This bottle easily converts into an infant bottle, sippy bottle or straw bottle by simply swapping the nipple out for another Pura Silcon Lid Bottle and collar crafted from safe, anti-bacterial, #304 stainless steel and medical-grade silicone Pura Silicone Big Mouth® Sport Top crafted from 100% medical grade silicone BPA-free, BPS-free, PP-free, Polypropylene-free, phthalate-free and will not leach toxins like plastic bottles and lids because our products do not contain any plastic! 100% medical grade silicone bottle sleeve Hand wash recommended Big Mouth® Sport Top is not designed for hot liquids