The Siemens 3VA9673-0JJ24 is a SENTRON TA4.1 circular conductor terminal — a wire connector designed for terminating two cables per unit, supplied in a pack of three. It accepts stranded copper or aluminum cable from 400 kcmil up to 750 kcmil, and finely stranded copper in the same range. For the 240–300 mm² stranded range the torque spec is 42.4 Nm. This is not a standalone breaker; it's an accessory meant for the 3VA55, 3VA65, and 3VA66 molded-case circuit breaker frames.
Stripped length is 1.1 inches — that's the bare conductor length you need before insertion. The terminal is an external circular conductor type, not a control-wire tap, so it's purely for power-side termination. Three units per pack cover the line, load, and a spare or a three-pole breaker.