MacBook Air 11-Inch Mid 2011
To open the Mac you need a PL4 Pentalobe screwdriver.
The EFI-ROM (U6100) is a WSON chip (64Mbit).
The ROM in on the bottom (hard to reach) side of the motherboard.
The 820-3024 and 820-2855 boards are almost identical. The difference in in the amount of RAM.