A slewing ring bearing or turntable bearing is a ball or roller bearing consisting of two concentric rings, either of which may contain a gear. This type of bearing enhances load support and power transmission in all directions and is often used to support heavy loads in slow speed applications and large equipment such as earth moving excavators and construction cranes. The unique power and versatility of slewing rings have made them increasingly valuable in a wide range of industries, including construction, industrial, robotics, machine tools and medical applications.