RHP SF25 4 Bolt Square Series: 4 Bolt Square cast iron unit castings are made from high-quality cast iron, and finished on unmachined surfaces with an electrostatic air-drying paint. These bearing insert and housing combinations include a grease nipple to facilitate re-lubrication. The bearing insert can be removed and replaced as required (Sold with the insert but inserts also old separately). The bearing insert has 2 grub screws to allow tightening against the shaft.