As the name implies, these Aligners are extra rigid. Because the material is firmer and stiffer, the Aligner can also be slightly refined in shape. The X-Stiff version is therefore slightly more compact and finer than its regular predecessor.
These long versions are for the short hook shanks. Hence the name X-Stiff Short Shank Aligner. The short hook shank is considerably extended by this aligner and so the hook point turns a lot faster, because the shank becomes fictitiously long. The advantage is that during the fight the Aligner stretches and thus creates the power of a short handle. Perfect!