Body Bottle is the easiest and lightest way to carry your fluids; Isobound Insulation prevents heat transfer from the user to the hydration. Engineered to keep fluids at an ideal temperature longer than a standard flask; Wide design with wide fill 42mm cap lets you easily fill with ice and drink mixes; Shrinks as you drink to eliminate sloshing and easily stores in pocket when empty; Made with ultra-durable, abrasion resistant TPU material and has Hydrapak's Beyound Lifetime Guarantee; Fits any of our UD Vests, Vestas, or Fastpacks; High-flow bite valve auto-seals after each sip, eliminating annoying drips; Can be frozen or filled with hot water (max temperature 60degC / 140degF); Safe and reliable, 100% BPA and PVC free