Retrieving description from another doc based on item number present

I'm new to the programming/macro arena and was wondering if someone could help me figure out how to retrieve some cell information from another document? I have attached a few example documents that help illustrate. What I am trying to do is to write a macro that can look at an Item Number present in Example #1, go to Example #2(the master list of Item Numbers) and find the corresponding Description for that Item Number(in the same row) and paste that description back into the blank cell in Example #1. The quantity of Item Numbers in Example #1 may change. But Example #2 (the master Item Number list) will always have all possible description matches.

Please let me know if I need to explain this in more detail, as I am new to this arena.

Thank you in advance for any help you can offer!

Example1 Sheet1 B2:

=INDEX('[Example 2.xlsx]Sheet1'!A:A,MATCH(A2,'[Example 2.xlsx]Sheet1'!B:B,0),1)

then copy down.

Thank you for your help!! This function worked perfectly!