Jewel bearings, jewels and pivots are miniature components used in instruments and controls that require low friction, long life, and non-magnetic properties. They are usually made of sapphire, ruby, or hard glass. Jewel bearings, jewels and pivots exhibit rare combinations of design characteristics. For over a century, jewel bearings, jewels and pivots have been used as reliable, low-friction devices to keep watches and timepieces working accurately. Cup bearings are jewel bearings that fit a ball bearing between two-cup jewels or semi-spherical pivots. Cup bearings are often used in vertical shaft applications, such as compasses and heat monitors. V-bearings are jewel bearings that are suitable for sensitive magnetic meter movements, compasses, encoders, turbine flow devices, and galvanometers. Unlike a miniature bearing that uses line contact, a V-bearing provides a low-friction coefficient because its moving shaft is near the point of contact. Glass V-bearings have slightly lower friction because their surfaces are fire polished.