What is the dipole moment of the most stable conformer of 1,1,2,2-tetrafluoroethane?

I want to know about the dipole moment of this molecule. I think the molecule has no dipole moment, but a book says me that it has a dipole moment. 




The dipole moment is 2.45 Debye. The molecule is dipolar as you have asymmetrical electron distribution around both the carbon atoms. 


Source: [*Complete Structure of Gauche 1,1,2,2-Tetrafluoroethane Determined by Microwave
Spectroscopy*, ***J. Phys. Chem. A***, 2000, 104, 9489-9493.](http://pubs.acs.org/doi/pdf/10.1021/jp001913i)


 3