Highland Home Wavy Indigo Design Stainless Steel Mug with Lid 12 oz. Mug is constructed of stainless steel which is known for its durability and ease of cleaning. Mug material prevents rust and corrosion. Stainless steel mugs are popular for outdoor activities, travel, and everyday use due to their lightweight nature and ability to withstand rough conditions. Features a full size handle for comfortable and safe grip. Dishwasher Safe.