Dust Proof & Waterproof: Level 5ATM. 1> Daily activities: Step count, distance, calorie calculation. ColorGun color, silver, rose gold. BT 5.4 BLE (Bluetooth Low Energy). Heart Rate Sensor HX 3918. Ring size（mm）No. 7,17.5 mm; No. 8, 18.3 mm; No. 9, 19.1 mm; No. 10, 20 mm; No. 11, 20.8 mm; No. 12, 21.6 mm; No. 13, 22.4 mm.
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