MEGA-2560 R31 Prototype

I need the datasheet of MEGA-2560 R31 Prototype with Manufacturer P/N to purchase it from you

These products are not manufactured by Arduino, so there is no way Arduino is going to be able to provide the information you request. You need to understand that there are many Arduino-compatible products made by other companies. Sometimes it is easy to mistake them for official Arduino products due to the way they are advertised. You can find the official Arduino products listed on the Products page:

and in the Arduino Store, though note that Arduino does sell some products made by other manufactures in the store as well (e.g. Paul Stoffregen's Teensy boards):

One of our forum moderators, Crossroads, does sell a product called the "Mega Screw Shield" that is not the same as the ones you are looking at, but similar. You are welcome to contact them for more information on that particular product:

Thank you very much

You're welcome. I'm glad if I was able to be of assistance. Enjoy!