Inner 304 Outer 201 Stainless Steel Heat Preservation And Cold Insulation, Humanized Design, Compact, Watertight, Safe, Easy To Use, Convenient To Carry, Beautiful And Practical, High Temperature Resistant, Environmental Friendly Material, Heat Insulation. Easy To Use, Easy To Store And Use. Baby Has Two Functions Of Heat Preservation And Cold Preservation. The Inner Tank Adopts 304 Stainless Steel And Vacuum Structure To Achieve Long-term Heat Preservation For 6-12 Hours Car, Office, Home, Business, Travel, Etc Easy To Clean, Can Be Recycled For Many Times, Not Bleached Microwave Not Available, Dishwasher Not Available