Meet Amazfit: a stylish, slim activity tracker that tracks your steps, distance traveled, calories burned, and sleep. You receive vibration alerts on incoming calls. The unit has a 10 day battery life. It is available in Moonbeam and Equator styles.
The center module is made of “hypoallergenic durable and water-resistant zirconium oxide ceramic.” You can get one of these for as low as $79 (depending on the model you choose).