Sunlink R15 - Smart Ring Heart Rate Blood Oxygen

Specification: Size: 75.00x75.00x45.00mm/2.95x2.95x1.77inch Ring inner diameter (mm): 6#16.5mm, 7#17.3mm, 8#18.1mm, 9#18.9mm, 10#19.8mm, 11#20.6mm, 12#21.4mm, 13.#22.2mm Weight: 3.0-4.0 g Chipset: AC6323 APP: Smart Health Compatible system: for Android 5.1 or above, for IOS8.0 or above BT: V5.0 Battery: 20mAh lithium polymer Life: 4-5 days, standby time 7-10 days Charging method: charging Charging time: about 1-2 hours Waterproof : IP68 Appearance material: epoxy resin + stainless steel (glazed) Package Contents: 1 x smart ring 1 x charging cable