From Jeffrey Tsai - As Xmultiple's Engineering Manager I would like to give you a complete answer with some background information.

(Yes, Xmultiple has an advanced solution for EMI reduction for 10GB applications.Before the XTFZ transformers the metal shielding use with 10Gb products was external to the transformer component chip. The Xmultiple 10Gb XTFZ integrates the metal shielding inside the component itself so the metal shielding is contained inside the housing of component. Other elements of the component such as coils and contact pads and pins are also inside the component chip and the metal shielding is position inside to shield the coils in a manner to completely reduce the electromagnetic interference).