Zojirushi's stainless steel vacuum insulation mug will keep your beverages hot or cold for hours. The compact design takes minimal space while maximizing capacity. Durable and sanitary these mugs have an 18/8 stainless steel interior. Each flip lid is tightly fitted for excellent heat retention, and features a safety lock to prevent accidental opening. The wide mouth on these mugs accommodate full-size ice cubes and makes cleaning easy. Diamond press exterior finish.