Price isn't everything
This is a genuine OMRON part. Cheaper copies sold under the same part number can look identical but may not seal, lock or carry current the same way.
Encoder Technology Incremental
Pulses Per Revolution 2000
Series E6B2
Maximum Revolutions 6000rpm
Output Signal Type NPN Open Collector
Shaft Type Solid
Shaft Diameter 6mm
Supply Voltage 5 → 24 V dc
IP Rating IP50
Overall Height 59mm
Switching Frequency 100 kHz