Apple Discontinues Intel-Based 21.5-Inch iMac - MacRumors
Identify your iMac model - Apple Support
iMac (21.5-inch, 2017) - Technical Specifications
Apple iMac (21.5-inch, Late 2015) review | TechRadar
Apple iMac Retina 4K 21.5´´ i3 3.6GHz/8GB/256GB SSD All In One PC Silver| Techinn
Apple rolls out first update to iMac desktop in almost two years
Apple 21.5-inch iMac review | 2014 | Digital Trends
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