This pillow block insert bearing is a self-aligning pillow block bearing, you can easily adjust or replace the bearing. The bearings have a wide inner ring with two set screws for securing to the shaft. Two bolt housing with ball bearing insert for plug and play assembly. Locking by locking screw for secure attachment to the guided shaft. Fine adjustment can be made between the inner bearing and outer locating ring angle. Features: Material: Zinc Alloy Inner Diameter: 8mm 2 Mounting Hole Spacing: 42mm Fixed Hole Diameter: 6.6mm. Package includes: 4 x ball bearings with bore diameter