The Siemens 3VA9254-0JG12 is a SENTRON wire connector TA1.2 designed as an accessory for the 3VA1 250 molded-case circuit breaker family. It combines a main power lug rated for 35–185 mm² copper or aluminum stranded cable with an integrated control-wire voltage tap-off — so you can pick up control power directly at the breaker line side without a separate terminal block. Strip length is 20 mm, and the terminal accepts copper stranded from 2 AWG up to 350 kcmil, aluminum stranded from 35 mm² to 185 mm². The IEC marking on the terminals reads 35-185 mm² CU/AL NNL.
This is a panel-mount lug kit, not a DIN-rail component. It bolts directly onto the line-side terminals of a 3VA1 250 frame breaker. The control tap-off gives you a convenient fused or unfused takeoff point for the breaker's own shunt trip, undervoltage release, or auxiliary contact power — keeps the control wiring inside the same footprint rather than running a separate tap back to a distribution block.