The Siemens 3VA9143-0JG11 is a SENTRON TA1.3 wire connector designed specifically for 3VA6 molded case circuit breakers in the 150 A and 250 A frame sizes. It's a circular-conductor terminal that includes a built-in control wire voltage tap-off, so you can pick up a control voltage directly at the breaker line side without adding a separate tap block.
Deployment context
These terminals mount directly onto the line-side lugs of 3VA6 breakers in a panel or enclosure. The integrated voltage tap-off saves a DIN-rail terminal block and the wiring to it — one less point to troubleshoot on a control panel build.