The Siemens 3RK1911-0CD40 is an ECOFAST power supply cable — 7 conductors of 2.5 sqmm each, prefabricated at one end with a HAN Q8/0 connector. It's the drop cable that brings 24 VDC or AC supply out to the field devices in a SIMATIC ET 200pro or similar distributed I/O island. The other end is unterminated, so you pull it through the cable tray and land it in the panel.
What the cable does and where it lands
The 7 x 2.5 sqmm cross-section is sized for the combined power and signal needs of an ECOFAST field distributor — typically three phase or DC pairs plus a PE conductor, all in one jacket. The HAN Q8/0 connector on the field end mates directly to the ECOFAST bus module's power inlet; the unterminated panel end lands on a terminal block or supply. Length is specified at order time in 10 cm steps, between >5 m and <10 m. That's a custom cut, not a shelf-stocked standard length, so lead time reflects the cut-and-terminate cycle.