Stainless steel vacuum insulation keeps beverages hot or cold for hours | One Touch Flip-Open Safely lock to prevent the lid from opening accidentally - Drinking straw pops-up when lid is opened, and stays covered and sanitary when the lid is closed. | 4 cm wide mouth opening -Ultra-lightweight and compact design | Stopper disassembles for thorough cleaning - Lid and straw disassemble for thorough cleaning. | Easy-to-clean nonstick coated interior. Made of BPA-free plastic and 18/8 stainless steel.