XUMIUZIY Smart Ring - IP68 Water Resistant Fitness Tracker

Spec: Item Type: Smart Ring Material: Stainless Steel, EP Battery Type: Lithium Battery Battery Capacity: 20mAh (Included) Battery Life: Approx. 5 days Charging Time: Approx. 30 minutes Thickness: Approx. 2.5mm / 0.1in APP: For Smart Health How to Use: Thread the needle with fine thread for sewing clothes, measure the position of wearing rings (the base of the finger). Use a ruler to measure the length of the thread (pull the thread straight, align the points on both sides) and make sure to measure slightly tight, otherwise it will be too big. Package List: 1 x Ring 1 x Charging Cable 1 x User Manual Note: When wearing, please make sure the optical sensor is in close with the skin of the fingertip to ensure accurate data.