OS HighSierra intel corei5ROM 8GBi-odata ssph-ut240k　（新品SSD）から起動するようにしてます。起動まで一分かかりません。内蔵HDはtime machineや保存用で使えます。有線のオリジナルキーボードとマウス付きですが写真の５番目のように染みみたいなのがあります。

Fair Condition*: Apple iMac 21.5-inch 2.8GHz Quad-core i7 (Mid 2011) MC812LL/A-BTO

OEM Apple iMac 21.5" A1311 Mid 2011 LCD Display Screen Lm215wf3 SD C2 661-5934 for sale online | eBay

iMac Intel 21.5" EMC 2428 Teardown - iFixit

Apple iMac 21.5-inch 2.8GHz Quad-core i7 (Mid 2011) MC812LL/A-BTO | mac of all trades

APPLE IMAC 21.5in CORE I5 2.5GHZ MID-2011 8GB 500GB SMART DVD MAC OS SIERRA (Renewed) : Amazon.co.uk: Computers & Accessories

Original For iMac 21.5" A1311 Motherboard Logic Board Mid 2011 Late 2011 820-2641-A 820-3126-A - AliExpress

iMac 21.5-inch (Mid-2011) Core i5 2.5GHz - HDD 500 GB - 4GB | Back Market

iSight*: Apple iMac 21.5-inch 2.5GHz Quad-core i5 (Mid 2011) MC309LL/A 3 | mac of all trades

iMac (21,5

APPLE IMAC 21.5in CORE I5 2.5GHZ MID-2011 8GB 500GB SMART DVD MAC OS SIERRA (Renewed) : Amazon.co.uk: Computers & Accessories

Apple iMac 21.5" desktop computer All-in-one A1311 Mid 2011 i5 2.5GHZ 8GB 500GB | eBay

A1311 iMac “Core i3” 21.5-Inch (Mid-2010) Repair Allen – Apple Mac Computer Repair Dallas , Laptop ,Desktop ,iMac ,MacBook iPhone iPad Data Recovery ,Virus

Apple iMac 21.5-inch 2.8GHz Quad-core i7 (Mid 2011) MC812LL/A-BTO | mac of all trades

iMac (21,5

Apple iMac 21.5" desktop computer All-in-one A1311 Mid 2011 i5 2.5GHZ 8GB 500GB