Apple Discontinued Entry-Level 21.5-inch iMac from 2017
Amazon.com: Apple iMac 21.5in 2.7GHz Core i5 (ME086LL/A) All In One Desktop, 8GB Memory, 256GB Solid State Drive, MacOS 10.12 Sierra (Renewed) : Electronics
Apple iMac 21.5-inch 4K Review: Style and Power
Apple Discontinues Intel-Based 21.5-Inch iMac - MacRumors
Review: 21.5-inch 2012 iMac takes two steps forward, one step back | Ars Technica
Apple iMac with 4K Retina display (21.5-inch, 2015) review: Apple packs more pixels into its smallest iMac - CNET
Apple's New 21.5 Inch iMac Has Upgradeable Parts — That's a Huge Deal