Carafa II fills the gap between Carafa I and Carafa III, roasted to a colour that sits squarely between the two — dark enough to make a genuine difference to a beer's appearance, without the maximum intensity Carafa III is reserved for. Like the rest of the Carafa line, it's dehusked before roasting, which is what keeps its flavour smooth and largely free of the sharp, tannic bitterness a husk-intact roasted malt like standard chocolate malt or black patent shows at a comparable Lovibond.
At 400-430 °Lovibond, a small addition already moves colour substantially, and like every heavily roasted malt it carries no diastatic power once the roasting process finishes — it contributes nothing to a mash's conversion capacity and can be steeped separately if a brewer prefers, though many German lager recipes simply mash it in alongside everything else. Schwarzbier and dunkel recipes reach for Carafa II when Carafa I's contribution isn't quite dark enough but Carafa III's full intensity would overshoot the target — a middle-ground choice for fine-tuning colour without an accompanying jump in whatever subtle roast character the malt does carry. Carafa I in a larger quantity, or Carafa III in a smaller one, both approximate Carafa II reasonably closely when it specifically isn't on hand, without needing a special order just to hit the exact middle tier of the line.