>>1771748In general, inner & outer plates (what I assume you're talking about) are not compatible, except for length variants within the same model.
But you can check for yourself. Go to this site:
si.shimano.comLook up your derailer model (usually stamped on the backside, starts with "RD-").
There is likely a pdf (name starts with 'EV') that has an exploded diagram listing parts interchangeable between models (if any).
Sometimes a bike shop can order these parts, sometimes you can find them on eBay, sometimes you can scavenge them from other broken/used units.
Pic is an example of the kind of document you're looking for.
