The Gulick tape measure makes it easy for anyone to accurately and repeatably measure various body dimensions by applying a calibrated tension. It is non-stretch, non-metallic tape measure. The most important part of the Gulick tape measure is its tensioning device, which provides a known amount of tension while a measurement is being taken. Each individual tensioning device is precisely calibrated to indicate a 4-ounce tension. The Gulick tensioning device uses a stainless steel compression spring. This guarantees that the calibration will last a lifetime, since it is impossible to "over-compress" a spring of this type.