Jern Body Fat Calliper Tester with User Manual Enjoy the ability to measure body fat easily by yourself, in the privacy of your own home, with the reliability and accuracy that is expected of today's registered medical devices. Recommended in body-for-life and endorsed by the world natural bodybuilding federation, accu-measure personal body fat testers have gold standard accuracy to within 1. 1 Percent of underwater weighing results. Comes with an original accu-measure personal body fat tester, men's and women's body fat measurement charts, instructions for body fat measurement, body fat tracking chart and questions and answers on body fat. Clinically proven to be more accurate than lengthy, complicated methods costing thousands of dollars. Raised markings provide clear, precise measurements. Patented audible and tactile click ensures correct, consistent and repeatable measurements. Get test results in seconds in three easy steps.