The Specialized 21OZ Big Mouth 2nd Generation is their best selling sports bottle and is now new and improved. With a comfortable ergonomic design the bottle is easy and comfy to hold while retaining its 100% leak free seal. New Big Mouth cap design features a wide water channel to deliver up to 50% greater flow than other leading bottles, plus improved functional outside grip. The large, soft and reliable poppet top is easy to activate and seals tight, making it 100% leak-free. Easy to grip and more flexible than the original Big Mouth bottle, so you can squeeze every last drop out. The bottle has been constructed from a BPA-free plastic made from 100% FDA food-grade materials and printed with non-solvent base (UV cured), CPSC-approved ink and bottle materials.