Samsung Rogue Extended Back/Battery?

[aintthatjustadaisy]

Recently I have been noticing that the battery on my Samsung Rogue is not holding a charge as long as it used to. I am going to buy a new battery. I want the extended life battery, but it is larger and comes with a back for the phone. Does anyone know if this will make the phone wider...or is it just to accommodate a larger battery while keeping the width of the phone the same?

Thanks