It's bad that the turbo manufacturers and distributors don't have a standard naming scheme, they are all over the place. Some name them after the inducer size on compressor, some on exducer size, some by the family (which have a million variations), some by horsepower ratings etc etc.
The one on my white car has an 82mm comp 50 trim front, 60mm 84 trim rear. GCG normally use the 82mm 56 tirim comp, 60mm 84 trim rear. The only real way to know is to measure it yourself - invoices can be wrong, wheels can be different to the i.d. tag on the catridge.. and salespeople are full of shit.