Our Big Mouth® Sport Straw is a free-flowing two-piece straw with a flip lid to eliminate spills and keep the tip clean. This all around top works equally well for 3 year olds, older kids, teenagers and even adults; in fact anyone seeking a 100% plastic-free, free flowing, leak-proof top for their stainless bottle. Convert your standard or insulated Kiki bottle into the perfect bottle for school age kids! Crafted entirely from medical grade silicone our Big Mouth® Sport Straw may very well be the only 100% plastic-free straw top on the market (except our valved sippy toddler straw). You can rest assured that you are getting the safest top for your child or anybody in the family.