Apple iMac 20" A1224 Early 2009 Mid 2009 Series Intel Socket 478 All-In-One Logic Motherboard 820-2347-A.

Apple Part Number: 820-2347-A
Compatible Part Numbers: 661-5136 31PICMB0040 CE3A
Compatible Models: Apple iMac 20" A1224 MB417LL/A Early 2009 Mid 2009 Series

Specifications:

CPU Socket mPGA478MN
x4 USB Ports
RJ-45 (LAN) Port
FireWire Port
Mini Display Port

Please Note: This motherboard does NOT come with a CPU.