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. Each flip lid is tightly fitted for excellent heat retention and features a safety lock to prevent accidental opening. Durable and sanitary these mugs have a stainless steel interior with non stick coating for easy clean up. If vehicle does not have an adjustable cup holder, please ensure that it will accommodate the diameter of 2-5/8."