1. Product Overview LSF 209 2F square four-bolt cast iron flange bearing assembly, matched with SU209-2F double set screw insert bearing. Equipped with double-sided 2F composite sealing combining metal flinger and NBR rubber lip to achieve two-stage mud and dust isolation. Two symmetric M10 set screws lock inner ring evenly, stable for forward and reverse rotation under heavy continuous vibration. Spherical outer ring provides ±2.5° self-aligning capacity to absorb shaft