Every MiiR product sold helps fund transparent giving projects. MiiR gives at least 1% of revenue to nonprofit organizations whose work empowers communities while benefiting the health of their natural environments. Every MiiR product comes with a Give Code that allows you to experience the story behind your purchase. Thermo 3D™ Double Wall Vacuum Insulation Technology. 18/8 medical grade stainless steel doesn't transfer flavor or leave you with a metal aftertaste in your mouth.