Pillow (plummer) block ball bearing units consist of an insert bearing mounted in a cast iron housing that can be bolted to a support surface. This variant is strong and stiff, and is suitable for applications with both constant and alternating directions of rotation. It has an inner ring extended on both sides and is locked onto the shaft by tightening a set screw on the inner ring, making it easy to mount. Strong. Designed for a constant and alternating rotation. Ready to mount. Lubricated and sealed bearing. Quick locking onto the shaft. Cost-effective.