Features: Accurate Measurement: Equipped with high precision strain gauge sensor, the hand dynamometer gives you accurate momentary digital reading of gripping power. user Friendly: Squeeze the hawith maximum isometric effort for at least 5 seconds. After testing, the LCD will automatically display the maximum grip value and a grip value status bar showing the status of weak, normal or strong according to age and gender preset for each test. -Adjustability: get an ideal grasp according to the size of hands. It is good fit for both big hand and small hand. -Easy to Read: Large LCD screen shows all measurements clearly on the same screen. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual measurement Description: Material: Plastic Size: 21.5x14x4.5cm USB rechargeable/battery dual-use Can be powered by AAA batteries or rechargeable dry batteries not included in shipment Package List: 1x Superspeed Muscle Strength Tester