Apple's thinnest watch ever. Apps for ECG Vital metrics Cycle Tracking and Sleep apnea. Fitness apps for temperature running activity surfing snorkeling and more. Smart Stack and Apple Watch plus Fitness+. Cellular - go without your phone using a carrier plan. Precision Finding. Battery life up to 18 hours. IP6X Rated dust resistant. Water resistant to 50 M. Gold titanium case with Sapphire front crystal. Case size: 42mm x 36mm x 9.7mm. S/M Starlight sport band fits wrists 130-180mm in circumference. Includes Magnetic fast charger to USB-C cable.