Feature:1. Automatic Synchronization: Long term storage, open the Bluetooth connection and log in to the APP, it will automatically synchronize and measure the change of each circumference for you, record the complete record, even if it is an increase or decrease of 1mm. 24 group members can be supported.2. Simple Operation: One person and one hand, one pull, one button and one close, even one person can operate it.3. Retractable Tape Measure: Freely retractable, measure at will, 150 cm 60 inches, one side is centimeters, the other side is inches.4. Large Digital Readout: The tape measure is durable, silky and hands free, showing every inch of progress you've made.5. One Handed Measurement: The tape measure card to the card slot can be used for one handed measurement, and the specially designed locking pin helps you to easily obtain your waist and biceps circumference by yourself or with one hand.Specification:Item Type: Digital Body Circumference TapeMaterial: Glass Fiber Nylon, ABSMultipurpose: Circumference Measurement Mode, Linear Measurement ModeBattery Type: CR2032 x 1 (Battery Not Included)Measurement Unit: cm/inchGraduation Value: Approx.1mm / 0.04inAccuracy: 2%Display Range: Approx.1.5m / 1.6ydMeasuring Range: Approx.0-150cm / 0-59.1inMultiple Circumference Measurements: Neck Circumference, Bust Circumference, Arm Circumference, Thigh Circumference, Calf Circumference, Shoulder Circumference, Waist Circumference, Arm Circumference, Body Circumference Score, Waist To Arm Ratio, Male And Female God IndexAPP Name: FitdaysAPP Languages: English, Simplified Chinese, Traditional Chinese, Japanese, Korean, Italian, Ukrainian, Vietnamese, Polish, Spanish, German, French, Thai, Portuguese, Arabic, Russian, Mongolian, Dutch , Greek, Bulgarian, Romanian, Czechoslovak, CzechProduct Size: Approx.7 x 7cm / 2.8 x 2.8in.Package List:1 x Smart Circumference Ruler1 x User Manual