1. Product Overview LEF211-2F four-bolt square cast iron flange bearing unit, matched with YEL211-2F double extended inner ring eccentric lock insert bearing. Double-sided 2F composite seal combines metal flinger and NBR lip rubber for two-stage mud & dust isolation. Eccentric locking collar clamps extended inner ring tightly for stable one-way rotation under heavy vibration. Spherical outer ring provides ±2.5° self-alignment to compensate shaft installation misalignment.