16GB (4GBx4) Team High Performance Memory RAM Upgrade For iMac “Core 2 Duo” 3.06 21.5-Inch (Late 2009) MB950LL/A iMac 10,1 1. The Memory Kit comes with Life Time Warranty. at Amazon.com
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
Memory Upgrades for Apple iMac 2011 Up to 32GB
CMS 8GB (2X4GB) DDR3 8500 1066MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core 2 Duo 3.06 21.5-Inch (Late 2009) - A35 at Amazon.com
8GB -2x4GB Memory Ram Upgrade for 27" Apple iMac 11.1 Core i5 2.66GHz Late 2009 | eBay
memory - What can be replaced/upgraded in a late-2009 iMac to make it run like a 2014-2016 iMac? - Ask Different
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
ssd - What are my hardware upgrade options for a late 2009 iMac? - Ask Different
Apple iMac 21.5" All-in-One Desktop Computer i3 3.07GHz 4GB Ram 500GB HDD Mac OS High Sierra MC508LL/A w/ Keyboard & Mouse - GRADE B
DDR3 RAM for Late 2009 iMac | MacRumors Forums
Install memory in an iMac - Apple Support
Timetec 16GB KIT(4x4GB) Compatible for Apple DDR3 1067MHz / 1066MHz PC3-8500 CL7 Dual Rank for iMac (Late 2009 21.5-inch / 27-inch) SODIMM Memory MAC RAM Upgrade for iMac 10,1 and iMac 11,1 at Amazon.com
How To Upgrade RAM in a Mac | Macworld
Apple iMac (27-inch, unibody, 2009) review: Apple iMac (27-inch, unibody, 2009) - CNET
Install memory in an iMac - Apple Support
How to Upgrade Memory in a Late 2009 21.5-inch or 27-inch iMac - YouTube
How to Upgrade Memory in a Late 2009 21.5-inch or 27-inch iMac - YouTube