Case Material: Base Metal Alloy (a durable brass/zinc alloy composition). It features a polished/brushed gunmetal ion-plated (IP) coating to give it that dark, metallic finish.
Caseback: Stainless Steel. The backplate that touches your skin is solid stainless steel to prevent corrosion from sweat and reduce skin irritation.
Dial Cover (Crystal): Mineral Glass. This is a heat-treated glass crystal that provides decent scratch resistance for everyday wear.