This is an old Apple iMac.
Serial Number: YM9120BSZE2
Model: – iMac (20-inch Early 2008)
Codename: – No codename assigned.
Build Country: – This unit was built in China or Czech Republic.
Build Year: – This unit was built in 2009.
Build Week – Your Mac was built in week 12 of that year (March).
Production Nr.: – This unit was number 400 to be built that week.