Measure the distance or size of spaces or objects using a tape measure, a flexible ruler usually spring-loaded onto a retractable mechanism for easy storage. It is possible for measuring tapes to be made of a wide variety of materials because they usually have linear measurements that cover a range of scales. There are several common types of retractable belt, all of which use curved metallic ribbons that remain stiff and straight when extended. These ribbons are locked together with lock mechanisms that keep the length in place. The belt retracts into a coil when not in use. When measuring circular or jagged surfaces, flexible fabric options are ideal. There are usually floating hooks or tangs at the end of measuring tapes, sometimes magnets, to hold them when in use, which is ideal when working alone.