ASUS CRW-5232AX? What is it?

Does anyone know exactly what an ASUS CRW-5232AX is? I can find no reference at all to that model on any of the ASUS sites. The only 52x32x52 internal CD-RW drives ASUS will admit to are the CRW-5232A, CRW-5232AS, CRW-5232A3 & CRW-5232A4. Could the AX model be a retail package of one the above drive models and, if so, which one?

Usually its the external version.

This is an internal drive. Unless it was previously removed from an external enclosure. The closest number ASUS shows on their global site is CRW-5232A(X)-U, which is an external drive. However, their only other external drive is shown as CRW-5232AS-U, so I would say that the -U denotes an external model.