Special features notifications Connectivity technology Bluetooth, Wi-Fi Battery cell composition Lithium Ion Screen size 44 Millimeters Brand Apple About this item HEALTH ESSENTIALS—Temperature sensing enables richer insights in the Vitals app and retrospective ovulation estimates. You’ll also get a daily sleep score, sleep apnea notifications, and be alerted if you have a high or low heart rate or an irregular rhythm. GREAT BATTERY LIFE—Enjoy all-day, 18-hour battery life. Then charge up to twice as fast as SE 2 and get up to 8 hours of battery in just 15 minutes. ALWAYS-ON DISPLAY—Now you can read the time and see the watch face without raising your wrist to wake the display. A GREAT FITNESS PARTNER—SE 3 gives you a healthy number of ways to track your workouts. With real-time metrics, you’ll hit your goals like never before. STAY CONNECTED ON THE GO—Send a text, make a call, download music and podcasts, and connect to emergency services all without your iPhone nearby. And now with speedy 5G, you can get fast performance on the go. SAFETY FEATURES—SE 3 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts. Check In can automatically notify a loved one when you’ve arrived at your destination. APPLE WATCH FOR YOUR KIDS—Set up Apple Watch For Your Kids, even if they don’t have their own iPhone. So they can call, text, and share their location. YOUR WATCH, YOUR WAY—Express yourself with dozens of easily customizable faces and a wide range of bands in different colors, styles, and materials.