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!