Amazfit Arc is a water resistant activity and sleep tracker with an optical heart rate sensor and scratch resistant OLED touch screen. Designed with comfort and simplicity in mind， Arc offers durable construction and industry leading 20 days of battery life on a single charge.COMPREHENSIVE TRACKINGStay motivated and meet your health goals with Amazfit Arc.With a tap on the display， you have easy access to the current time， your daily step count， distance traveled， calories burned， heart rate and battery status， without the need for phone access. Get vibration alerts for incoming calls and set vibrating alarms at custom timesHIGH-END TECHNOLOGYInstantly check your health stats on the Arc's 0.42 inch UV-coated and scratch-resistant OLED touch screen display. With a power-efficient optical heart rate sensor (PPG) and accelerometer， a single charge provides 20 days of battery life. The Arc companion app for iOS and Android stores all your data; including heart rate， calories， steps， sleep (light and deep)， activity， and more.TOUCH SCREENScratch-resistant OLED touch screen display.HEART RATEOptical heart rate sensor for Amazfit Arc and Pace.20 DAYS OF BATTERY LIFEFrom a single charge.SMART NOTIFICATIONSGet notifications for incoming calls and messages.ACTIVITY TRACKINGSteps， distance， active calories， heart rate.SLEEP TRACKINGAnalyze your sleep patterns.LIGHTWEIGHTYou'll barely notice wearing it.WATER RESISTANTWorks rain or shine.