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 Tape Material: Glass Fiber Nylon, ABS Multipurpose: Circumference Measurement Mode, Linear Measurement Mode Battery Type: CR2032 x 1 (Battery Not Included) Measurement Unit: cm/inch Graduation Value: Approx.1mm / 0.04in Accuracy: 2% Display Range: Approx.1.5m / 1.6yd Measuring Range: Approx.0-150cm / 0-59.1in Multiple 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 Index APP Name: Fitdays APP 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, Czech Product Size: Approx.7 x 7cm / 2.8 x 2.8in. Package List: 1 x Smart Circumference Ruler1 x User Manual