My first and most important suggestion: Do not buy an aftermarket CK12 capsule copy without first hearing every brand personally in your mic!
... even AKG's own, modified, 2nd gen CK12, which was supposedly specifically modeled after a very good specimen of an originally CK12, has disappointed almost all who bought into that claim.) ...
Probably refering to the TLII capsule, a copy of the earlier CK-12 designs with a large 10k hz lift built in.