Slim Guide Skinfold Caliper Kit includes: Slim Guide Skinfold Caliper (black); BMI Tape Measure; Dermographic Marker to mark test sites; Vinyl Transport Bag. The Slim Guide Skinfold Caliper is the most accurate affordable caliper. Produced since 1976 it is the most widely used caliper in the world. Used by professionals and researchers world wide it is the only low cost skinfold caliper accurate enough for professional use. It has the same jaw area and spring tension as the Harpenden and studies have shown that the measurements obtained are very comparable. Includes the book "How To Measure Percentage Bodyfat". Durable ABS construction. Thus the Slim Guide is almost indestructible. The springs and hardware are made of stainless steel adding to its high quality. SPECIFICIATIONS: Range: 80mm; Weight: 7 ounces (200 grams); Dimensions: 7 x 12 x 1 inches (18 x 30 x 2.5 centimeters); Materials: Plastic, metal spring. BMI TAPE MEASURE: With the body mass index (BMI) tape measure you can monitor and assess changes to your body, including waist circumference and waist-to-hip ratio. Then use the calculator function to quickly determine BMI and obesity risk. FEATURES: Range: 0-150 centimeters in circumference; One-handed use and push button retraction; BMI calculator function; Colored tape for the classification of obesity risk; Metric system for length; BMI calculation uses metric system (meters) or standard (feet/inches) systems for height, and metric (kilograms) or stones (st) for weight. How to To identify Obesity Risk: 1. Measure waist (note that one side is for males, the other for females). 2. Use the following colors to identify obesity risk: Green = healthy, Orange = moderate risk, Red = obese ("central obese") and high risk of heart disease. To calculate BMI: 1. Using the dial, line up your weight (in kilograms) with your height (in meters). 2. See BMI reading in window to determine if you are underweight, healthy, or overweight, or very overweight.