The Oura Ring 4 Smart Ring Activity Tracker Gen 4 in size 10 and silver color is a stylish and high-tech tool for tracking your fitness and wellness. Made of titanium, it features optical bio-tracking sensors to accurately measure your heart rate and sleep patterns. Compatible with both Android and iOS operating systems, this unisex activity tracker is worn on your hand and provides insights into your daily activity tracking and wellness tracking needs. With features like average heart rate monitoring and sleep tracking, the Oura Ring 4 is a sleek and functional addition to your fitness technology arsenal.