Cylindrical roller bearing NJ2311-E-XL-MPAX-QP51-C4 is a single row design with two ribs on the outer ring and one rib on the inner ring, giving it a semi-locating function that carries axial load in one direction while allowing free axial displacement in the other. Bore diameter is 55.0 mm, outside diameter 120.0 mm, width 43.0 mm, and net mass is 2.46 kg. The bearing has the E design with reinforced roller complement for increased radial load rating, uses an MPAX cage, and is manufactured in radial internal clearance group C4. Limiting speed is 10400 1/min and reference speed is 4500 1/min. The semi-locating configuration with one-directional axial guidance allows this bearing to support a shaft while compensating for thermal expansion or misalignment along its free side. The C4 clearance suits applications where operating temperatures or fits reduce the internal clearance below the standard range, keeping the roller set from becoming overloaded. The E design increases load carrying capacity within the same envelope dimensions, and the MPAX cage guides the rollers for stable operation at the stated speed limits. No sealing is integrated, so lubrication and contamination protection must be provided externally through the housing arrangement.