toshiba satellite C55 T-A ram upgrade

[Dollyann]

Could someone tell me what is the maximum ram for a toshiba satellite C55 T-A computer (currently 4gb)

 

[Darkbreeze]

What is the exact model number? For example, C55T-5218 or C55T-5123. Small differences in actual model number could relate to completely different hardware within the base model.