@simayunguang47 

I am wondering why you keep on asking those Bitcoin wallet file extensions mate? What are doing with those files if you don't mind? It's just weird that your asking questions about that thing since google is free and broad. Are you some sort of a dev or something?

I don't think this helps but kindly check:

@simayunguang47 

I am wondering why you keep on asking those Bitcoin wallet file extensions mate? What are doing with those files if you don't mind? It's just weird that your asking questions about that thing since google is free and broad. Are you some sort of a dev or something?

I don't think this helps but kindly check:
https://en.bitcoin.it/wiki/Wallet