Pillow block bearings, flange bearing units, bearing blocks, and take-up bearings units all consist of a housing with a bearing mounted in it. They are available in a variety of materials, mounting configurations and various bearing features. Each mounted unit, including a mounted bearing, acts as a system to position the bearing securely for reliable operation. pillow block ball bearing units consist of an insert bearing mounted in a housing, which can be bolted to a support surface.