Need to clear confusion on two variety of same [Seiko SRPD55K1]

I want to buy Seiko [SRPD55K1] but when I check it on a luxe app, it shows two models with same model no. Only description has little different. One it says 43 mm dial diameter and other Occation Casual. Other it says 42.5mm dial diameter Occation as formal. Model no quoted is same. Where can I find comparison and differences in these two watches as no where I can find this difference details.