The Siemens 6ES7922-3BC50-0AB0 is a pre-wired front connector for SIMATIC S7-300 digital I/O modules, terminated with 20 single cores (0.5 mm², H05V-K) in a 2.5 m cable bundle, blue sheath, screw-type terminal block on the enclosure side.
Rated 24 V and maximum 30 V — these are the voltage limits on the I/O module side; the cable and connector are sized for the 24 VDC digital signals common in S7-300 racks, and the 30 V ceiling covers the typical 24 V supply plus a margin for transients. 20 poles and 20 channels mean one connector handles a full 20-point digital I/O module (e.g. SM 321 or SM 322) without splitting signals across multiple connectors.
The 2.5 m cable length lets you route the bundle from the module slot to a terminal strip or junction box inside the enclosure without splicing; the blue PVC sheath and consecutively numbered cores (1 to 20) simplify wire identification during commissioning.