A question for the Citizen experts

I have just acquired a 48mm ecozilla (not the Orca). The model number shown on the caseback is B873 but I am led to believe that this model is also known as the BJ8050. Can anyone confirm that they are one-and the same model? I need to buy the strap adapter and they seem to be advertised separately for B873 and BJ8050. Obviously don’t want to get the wrong one, so grateful for any help/advice here.
Rob