Meet the ultimate mountain sports watch! Designed for endurance athletes, the COROS Apex 4 42mm provides reliability in extreme conditions. Enjoy up to 41 hours of battery life in Endurance GPS Mode. Its titanium bezel construction offers rugged durability as you explore the outdoors. Whether you're an ultramarathoner or multi-day explorer, the COROS Apex 4 42mm helps you find new heights! Alpine Grade Engineering: Lightweight, durable, premium design Sapphire Glass with 3rd generation MIP Touch Screen Lightweight and durable Grade 5 Titanium bezel Reinforced lugs for added durability and comfort Battery, Screen, Weight 1.2 inch display, 45 grams Battery Life: 41 hours in Endurance GPS mode, 34 hours in High GPS mode Sensors: Optical Heart Rate, Blood Oxygen, ECG, Dual-Range Barometer, Water Depth Sensor, Compass Hardware: Memory-in-Pixel Screen for deeper colors & better contrast in sunlight 30x faster map and graphic loading than APEX 2 Microphone for Voice Pins Speaker to take hands-free calls Alerts and Weather: Nutrition, Heart Rate and Off-Course Alerts Storm, Safety and Altitude Real-time weather, wind speed and air pressure Save up to 5 locations to view weather directly on your watch Recovery and Wellness: Sleep Tracking and Sleep Quality Wellness Check Recovery Timer Heart Rate Variability Training and Connectivity: Free Workouts and Training Plans from COROS Audio Alerts during workouts and strength training animations Create and Sync routes directly from the COROS app Sync with Strava, Training Peaks, Apple Health and more