[Size Before You Buy：Please according to the wearing instructions on the details page first measure your finger circumference then calculate the inner diameter of your finger find the corresponding ring size number and select it. Smart Ring：The HARMNHLT smart ring health tracker can check your exercise time distance traveled calories burned and the quality of your sleep through the APP. Remote Photography：Smart Rings for Men Smart Ring for women supports remote photography function allowing users to remotely control their phone to take photos when needed. Just shaking your finger twice quickly and the shutter button will be pressed. Free your hands when taking photos "5ATM Waterproof：The Fitness Ring meets the 5ATM waterproof standard. Whether its daily hand washing showering or shallow water swimming theres no need to remove the ring. We can provide reliable waterproof protection making wearing more convenient and worry free." No APP Subscription Required：Blood Pressure Ring Connect to your phone with one click BluetoothThe Health Tracker track your health and exercise data anytime and anywhere and easily manage your health through the app without additional subscription fees. The exclusive mobile app provides a seamless data browsing experience and all functions are free to open making health management more convenient and worryless "Looking for The Perfect Gift? ：This revolutionary smart ring accurately tracks sleep activity and stress in a stylish way. Ideal for your lover elders and friends its also a practical and valuable gift for Christmas Valentines Day Halloween Thanksgiving and New Year."]