FDA approved medical device, smart watch for blood pressure monitoring, certified by US, European and China authorities Heartbeat and heart rate monitoring function Sleep quality and sleep time monitoring function Activities and step tracking functions Bluetooth 5.3 connections, set up to monitor health info of you or your love ones on APP Touch Screen. Large display size 1.39" x 1.15". Applicable wrist circumference: 5.3" x 8.5" P67 waterproof, wear it anytime without worry Built-in Lithium battery This is a certified medical smart watch, tracking all the health infomation you care. The mini air bag blood pressure monitor provides accurate testing (certified by US,European and China authorization offices). It also monitors blood oxygen, heart rate, steps, sleeps and much more. It is connected to your phone via Bluetooth. All info is shown up in your phone, and the phones of your family members if it is set up that way. It alerts you and your family if anything goes wrong. It offers the peaceful minds and relax lives. It is a smart watch anyway, with all smart watch necessary features, like showing messages, tells time, and much more. Note: if the watch is worn too loosely or too tightly, it will affect the measurement results. The testing gesture during measuring is also crucial. You need to have correct band length and testing gesture for accurate results. Please refer to the details in the instruction manual or the videos. There is a soft measuring tape provided in the box, use it and follow the instructions to adjust the band length. If you have any problems during the use process, please be sure to contact our customer service for guidance.