It is made of ABS plastic, stylish and lightweight with superior accuracy and reliability. Quickly provides exact measurement of body fat thickness. Extremely easy to use, simply squeeze calipers until it is hard to squeeze anymore further A vital piece of equipment for anyone in terms of health as it allows users to see progress and how healthy they are The standard skinfold caliper with high precision is good for research, clinical and home applications. Specification: Range: 0~50mm/0~2 inch Resolution: 0.1mm/0.01 inch Accuracy: 0.2mm/0.01 inch Working Temp: 0C ~ +40C Storage Temp: -20C ~ +70C Manual Power off Battery: 1 x 3V CR2032 Battery How to use: 1.Close the Jaws,then Press the inch ZERO inch Switch to Set Zero. 2.The Site You will Use for Skinfold Measurement is the Belly (Approximately one Inch above the Right Hipbone). 3.While Standing, Firmly Pinch the Suprailiac Skinfold between your Left Thumb and Forefinger, Place the Jaws of the Digtal Body Fat Caliper over the Skinfold, while Continuing to Hold Skinfold with the Left Hand. 4.Press the Jaws until you Feel Slight Pain,Then press "HOLD" Switch to Keep the Measurement, After Reading Your Measurement, Press inch HOLD inch Switch to Continue, Repeat Three Times and Use the Average as Your Measurement, Refer to the Body Fat Interpretation Chart to Determine Your Body Fat Percentage and what is Means. 5.If the button doesn't work,please check the battery,it needs 1 x 3V CR2032 battery. Package included: 1 x Digital Body Fat Caliper