The West Loop Thermal Mug has an ergonomic shape andoffers the high quality that you would expect from Contigodrinkware. It has the patented Autoseal? technology whichmakes the mug 100% spill-proof and leak-proof. Simply pressthe button to sip from the cup and release to seal. Thedouble-wall design has stainless steel inside and out withvacuum insulated technology to keep beverages hot for up to 5hours and cold for 12 hours. 470ml capacity. BPA free.