| KOYO NJ2304E+HJ2304E Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| NSK 2304 K Bearing | 20 | 52 | 21 | NSK | Self-aligning Ball Bearings |
| KOYO 2304K+H2304 Bearing | 20 | 52 | 21 | KOYO | Self-aligning Ball Bearings |
| SKF 4304 A TN9 Bearing | 20 | 52 | 21 | SKF | Deep Groove Ball Bearings |
| NACHI NUP 2304 Bearing | 20 | 52 | 21 | NACHI | Cylindrical Roller Bearings |
| KOYO NUP2304R Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| KOYO NUP 2304 Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| KOYO NJ 2304 R+HJ 2304 R Bearing | 20 | 52 | 21 | KOYO | Cylindrical Roller Bearings |
| NTN 2304 Bearing | 20 | 52 | 21 | NTN | Self-aligning Ball Bearings |