C1904 and C1905 difference?

[kartikmandavia]

is c1904 is defective model? having heat problem,
diffrence between c1904 vs c1905

[Uliwooly]

The difference are the frequencies not that one is deffective 

HSDPA 900 / 2100 - C1905, C2005

HSDPA 850 / 1700 / 1900 / 2100 - C1904, C2004

[nagi8]

can a data card be connected to my c 1904 model with usb otg ?
my phn is getting heated drastically if 3g is on for even 30min continuously ?? is this usual or a defect ?