The SENTRON 3VM9253-0JA12 is a box terminal set — three pieces of the TS1.4 profile — designed as an accessory for the 3VM 250 molded-case circuit breaker family. It accepts copper conductors from 4 AWG up to 350 kcmil, both stranded and finely stranded, which covers the full range of feeder and branch-circuit cable sizes you'd typically land on a 250 A frame breaker.
Each terminal takes a stripped length of 0.8 in, so strip your cables to that mark before insertion — no guessing. The box-terminal design clamps the conductor with a screw, giving a gas-tight connection that holds up under thermal cycling in a warm panel. Rated for copper only; if your install uses aluminum, you'll need a different lug.